Applied Probability and Statistics_Wrong!

Question 1

Is the following statement true or false?
−16 ≠ (−2)4

Answer 1

False

Question 2

Display x less than or equal to 4 using interval notation.

a (−∞,4)
b (−∞,4]
c (4,∞)
d [4,∞)

Answer 2

(b): (−∞,4]
This notation shows all values of
𝑥
that are less than or equal to 4. The bracket “

Question 3

−10 belongs to which set(s) of numbers?
a) real
b) real, rational
c) real, rational, integer
d) real, rational, integer, whole

Answer 3

real, rational, integer

Question 4

√3

is a(an)

a) integer.
b) only a real number.
c) rational number.
d) whole number.

Answer 4

b) only a real number.

Question 5

−10

belongs to which set(s) of numbers?

a) real
b) real, rational
c) real, rational, integer
d) real, rational, integer, whole

Answer 5

c) real, rational, integer

−10 is a number with no decimal or fractional component and is an integer. If a number is an integer,
it is also rational, because it can be written as a fraction, and it is real, because it can be placed on a number line.

Question 6

This week, your commutes into work have taken 4, 14, 12, 17, and 8

minutes. What is an accurate estimate for the number of minutes you have spent driving?

a) 45
b) 60
c) 65
d) 70

Answer 6

b) 60

Feedback: The correct answer is b. The approximate sum is 5+15+10+20+10, which is 60 minutes.

Question 7

What number system does −2 belong to?

a) whole numbers
b) integers
c) rational numbers
d) real numbers

a) A and B
b) B and D
c) A, C, and D
d) B, C, and D

Answer 7

B, C, and D

−2
is an integer (because it does not contain a fractional or decimal component), a rational number (since it can be written as a fraction),
and a real number (because it can be placed on a number line).

Question 8

During a three-day air show, there were 17,351 people on Friday, 24,718 people on Saturday, and 33,512 people on Sunday. What was the estimate attendance for the weekend?

a) 74,000
b) 76,000
c) 78,000
d) 80,000

Answer 8

b) 76,000

The estimate number of people is 17,000+25,000+34,000, which is 76,000

Question 9

An inch is 136 of a yard. How many inches are in 12 of a yard?

Answer 9

18 ( not 18/36)

Question 10

What multiple of 7 is closest to −40?

Answer 10

-42 (negative signs beware)

Question 11

3/4 − 6/16 = 6/16 = 3/8 (Careful of breaking down fractions)

Question 12

4 × 8/3 = 10 2/3 (Careful with 4 x 8 is not 42. It is 24)

Question 13

What percent of 65 is 32? 42.2 (round your answer to the nearest tenth.) %

Question 14

Type in the formula you would use if you had a temperature in Fahrenheit and you wanted to convert it a temperature in Celsius:
C = (F - 32) x 5/9
F = C x 9/5 + 32

Answer 14

C = (F - 32) x 5/9

Question 15

Which of the following is the least common denominator (LCD) of 5/6and 3/12?

Answer 15

12

Question 16

Please evaluate the following expression: (Reduce your answer to its lowest terms.) −7/59÷4/34=?
a −1/10 11/71
b −78/13
c −7/34
d −5/23

Answer 16

−78/13

Question 17

If the cost of a product is $50 per 5 cubic feet (cu. ft) of volume, what is the cost of the product per cubic foot?

a) $5 to 1 cubic foot (cu. ft)
b) $10 to 1 cubic foot (cu. ft)
c) $1 to 2 cubic foot (cu. ft)
d) $50 to 1 cubic foot (cu. ft)

Answer 17

b) $10 to 1 cubic foot (cu. ft)

Question 18

How many kilograms are there in 10,000,000 micrograms?

a) 0.01
b) 10
c) 100
d) 1000

Answer 18

a) 0.01

The correct answer is a. 0.01
kilograms is equivalent to 10,000,000 micrograms:
10,000,000 mcg1×0.000001 g1 mcg×1 kg1000 g.

Cancel units and solve. 10,000,000×0.000001÷1000=1,000,000=.01 kg.

Question 19

Round 119.928 to the nearest tens. (TENS❗❗❗)

a) 110
b) 120
c) 119.9
d) 119.93

Answer 19

b) 120

The correct answer is b. The number in the tens place is a 1, and since the digit that follows is a 9, the number is rounded up to 120.

Question 20

1−2s−3t.

Answer 20

Alter the fraction to reflect a multiplication operation,
and with the new multiplication operation, we can use distributive property and simplify the expression.
Therefore, 7−14s−21t7=17⋅(7−14s−21t)=(17⋅7)+(17⋅−14s)+(17⋅21t)=1−2s−3t.

Question 21

2m - 2n is correct

Answer 21

The answer is 2m−2n. There are two instances in which the distributive property should be used. For (2m+4), imagine an invisible 1 outside the parentheses and distribute it to the terms inside the parenthesis. For −(4n+8)2, alter the fraction to reflect a multiplication operation, and use distributive property with the new multiplication operation. With all relevant terms distributed, simplify the expression by combining
like terms. Therefore, (2m+4)−(4n+8)2=1(2m+4)−12(4n+8)=2m+4−2n−4=2m−2n.

Question 22

Watch out for Aplphabet 0 LK vs and KL and most variable first
9KL + 4K is correct

Answer 22

The answer is 9KL+4K.
First, combine your like terms: 6K and −2K outside the parentheses, K and 2K inside the parentheses. 6K+3L(K+2K)−2K=4K+3L(3K). Then, multiply the 3L to the 3K inside the parentheses. Our final answer is 4K+9KL. Reverse the terms since two variables take precedence over one: 9KL+4K.

Question 23

3w - 1 is correct ❗watch the negative sign (not 3W + 1)

Answer 23

The answer is 3w−1
. First, combine like terms in the denominator. The 4.5w and the −4.5w will cancel out, and combining the constant terms gives 12−9=3. Then, alter the fraction to reflect a multiplication and distribute. Therefore, (9w−3)(4.5w+12−4.5w−9)
=(9w−3)3
=13⋅(9w−3)
=3w−1.

Question 24

17w−9=4w+19
17w−4=4w+24

Answer 24

17w−9=4w+19
17w−4=4w+24
Question 3.
yes is correct
×
The answer is yes. You can see that 5
has been added to the right side of the equation because −9 became −4. 19 became 24 on the right side of the equation, so 5 was added.
Since 5 was added to both sides of the equation, the principle of equality was upheld.

Question 25

c23=87(w−14)+90
c23+7=87(w−14)+83
no is correct
×
The answer is no. On the left side, 7
has been added, but on the right 7 has been subtracted.
So this equation does not show the priciple of equality.

Question 26

$377250 is correct
×
The answer is 350=v+100
. Before we can determine total revenue, we must first calculate the revenue generated by the sales to each customer based on their individual discounted price. Customer A purchased 140 units earning a 10% discount off the per unit price, so Customer A is effectively charged 90% of the price per unit. Customer B purchased 225 units earning a 15% discount off the per unit price, so Customer B is effectively charged 85% of the price per unit. Customer C purchased 60 units and based on the discount schedule, this order did not qualify Customer C for a price discount. Therefore, Customer C is charged full price.

Therefore our equation is:

R=(140×($ 1000×.90))+(225×($ 1000×.85))+(60×($ 1000))

Question 27

39−2a=6a+13−6, a= (when subtracting -2a)

Answer 27

4 is correct
×
The answer is 4
. To simplify the equation above, first combine like terms.
Then, use the subtraction principle of equality to isolate a on one side of the equation to solve for its value.
39−2a=6a+13−6
39−2a=6a+7
(39−39)−2a=6a(+7−39)
−2a=6a−32
−2a−6a=6a−6a−32
−8a=−32
−8a−8=−32−8
a=4.

Question 28

y > 2x -4
Suggested/Sample Response

Answer 28

y≥2x−4

Question 29

careful of the sign switched twice

Answer 29

x < 1/7 is correct
×
Correct. Since x+5
is divided by 3 multiply both sides by 3:
3⋅x+53<3⋅x−7−4
x+5<3x−21−4
Multiply both sides by −4 and reverse the sign
−4(x+5)>3x−21
−4x−20>3x−21
−7x>−1
−7x−7<−1−7
x<17

Question 30

Which of the following pairs are not like terms?

Answer 30

12t and 12T

Question 31

Solve for x in the following equation:

18=6−2(x+6)

a) −12
b) −6
c) −3
d) 0

Answer 31

Correct Answer Un-checked a) −12

Wrong Answer Checked b) −6
Un-checked c) −3
Un-checked d) 0

Feedback: The correct answer is a. Apply the distributive property for −2
, which is 18=6−2x−12. Combine like terms on the right side of the equation, which is 18=−2x−6. Add 6 to both sides of the equation. 18+6=−2x−6+6, which is 24=−2x. Divide both sides of the equation by −2, which is 24÷−2=−2x÷−2; −12=x.

three points plotted on a coordinate plane labeld A, B, and C. A corresponds to -3 and 2; B corresponds to -3 and -3; C corresponds to 3 and -1;

Question 32

Careful of answer - (wrong coordinates 0-duh!)

Answer 32

Correct Answer Un-checked a) (−2,−3)
Wrong Answer Checked b) (−3,−2)
Un-checked c) (−2,3)
Un-checked d) (−3,2)

Question 33

ab−ac+a
when a=2, b=−1, c=−3

Answer 33

c) 6

Feedback: The correct answer is c. Replace a with 2
, b with −1, and c with −3 in the expression, then perform the operations. 2−1−2(−3)+2=−2+6+2=4+2=6.

Question 34

Identify the number of terms and the coefficient for the x term in the expression:

−2x+8

a) Terms: 1; Coefficient: −2
b) Terms: 1; Coefficient: 8
c) Terms: 2; Coefficient: −2
d) Terms: 2; Coefficient: 8

Answer 34

c) Terms: 2
; Coefficient: −2

Question 35

Solve for d:
d÷2=−14

a) d=−7
b) d=−28
c) d=−12
d) d=7

Answer 35

(your incorrect answer) a) d=−7
Incorrect.

The correct answer is b. In order to solve for d
, we must alter the equation so that it’s by itself. The first step is multiplying both sides of the equation by 2 to eliminate the ÷2 on the left side. The equation then reads d=−14⋅2, so d=−28
b) d=−28
c) d=−12
d) d=7

Question 36

I got this right - just wanted to take notes
I Would summarizing this data with a measure of center be a good choice? If yes,
please state which measure you would use and why. If no, please rationalize your answer.
Your response

No. This graph has a bimodal distribution. The most serious tasks out number ever other task except
the least serious problem. That being said, it would not be ideal to find the center because the
center is not the most important task at this time.
Suggested/Sample Response
The mean? No, not a good choice. The median? No, not a good choice. The mode? No, not a good choice.
I wouldn’t try to summarize the data with a measure of center. A good choice: The data is better seen on
a graph to illustrate the unusual pattern.
Often referred to as U-shaped, it has peaks at 1 and 7. This is a special case of bimodal data.

Answer 36

No. This graph has a bimodal distribution. The most serious tasks out number ever other task except
the least serious problem. That being said, it would not be ideal to find the center because the
center is not the most important task at this time.
Suggested/Sample Response
The mean? No, not a good choice. The median? No, not a good choice. The mode? No, not a good choice.
I wouldn’t try to summarize the data with a measure of center. A good choice: The data is better seen on
a graph to illustrate the unusual pattern.
Often referred to as U-shaped, it has peaks at 1 and 7. This is a special case of bimodal data.

Question 37

What the signs, subtract from IQR
What is the value below which any data values are outliers?

Answer 37

25 is correct
×
Correct. Outliers are defined as any points that are more than 1.5×
IQR above Q3 or below Q1. To find the value below which any data values are outliers,
multiply the interquartile range
(IQR) by 1.5. (IQR) ×1.5=52×1.5=78. Subtract 78 from the first quartile =(Q1)−78=103−78=25.

Question 38

I got this but look out for IQR
3. The average female height in the U.S. in 2010 was 63.8 inches, with a standard deviation of 2.7 inches.
Assuming a normal distribution:

95% of the data is between what values? Enter the letter that corresponds with your answer choice.

55.8

inches and 62.9
inches
55.8
inches and 69.2
inches
58.4
inches and 69.2
inches
58.4
inches and 62.9 inches

Answer 38

C is correct
×
Correct. The key to solving this problem is using what we know from the Standard Deviation Rule, specifically that 95%
of the data will fall between 2 standard deviations from the mean. Since we know that the standard deviation is 2.7 inches,
we can calculate that 2 standard deviations is equal to 5.4 inches (2.7×2). Now knowing this value,
we can determine the values that 95% of the data will fall between. To obtain the first value, we will subtract
5.4 inches from the mean: 63.8 inches − 5.4 inches = 58.4. To obtain the second value we will add 5.4 inches to the mean: 63.8 inches + 5.4 inches = 69.2 inches.
Therefore, 95% of the data will fall between 58.4 inches and 69.2 inches.

Question 39

68 % is correct
×
Correct.These two values, 61.1
and 66.5 inches, are values that represent one standard deviation below and one standard deviation above the mean.
Using the Standard Deviation Rule,
we know that 68% of the data falls between one standard deviation from the mean. Therefore, the answer is 68%.

Question 40

I missed the % for standard deviation
4. Suppose that ArriveOnTime Airlines reports the average on-time ratings for all flights in their network is 98.6 and the standard deviation is 0.6

. Assuming a normal distribution:
a. What percent of ArriveOnTime Airlines’ flights will fall within one standard deviation of the mean?
Question 14. %
b. What percent of the flights would you expect to have an on-time rating below 96.8
?

.15 % is correct
×
Correct. 96.8
is 1.8 lower than the mean on time rating of 98.6. (98.6−96.8=1.8). We know that the standard deviation is .6,
so dividing the difference of on time rating of 1.8 by .6, we get a value of 3. This tells us that 96.8 is three standard deviations lower than the mean. Using the Standard Deviation Rule, we know that 0.15% of a population falls below three standard deviations from the mean. Therefore,
the percent of the flights that we would expect to have an on time rating below 96.8 is 0.15%.

Question 41

I had to add these two to get the Q2
1) Find the second quartile (Q2

) for the following data set:

{41, 76, 16, 8}

a) 14
b) 16
(your correct answer) c) 28.5
Correct.

The correct answer is c. Q2
, also known as the median, is the midpoint of the data set. Here, with an even number of values, Q2 falls midway between 16 and 41, which is 28.5
.
d) 58.5

Question 42

I did not break this into quartiles

6) Identify the five-number summary for the following data set:

{ 10, 50, 14, 49, 81}

a) 10,12,49,65.5,81
tep-by-Step Calculation:
Sort the Data: {10, 14, 49, 50, 81}

Minimum: 10

Median: The middle value is 49 (3rd value in the sorted list)

First Quartile (Q1): The median of {10, 14} is 12.

Third Quartile (Q3): The median of {50, 81} is 65.5.

Maximum: 81

Question 43

know mode better
4. Mode is a measurement not often affected by outliers. True or False?

a. True

Correct. This is a true statement. Mode measures the most frequent value in a data set. A significant outlier would not necessarily affect the mode of a data set.

b. False

Incorrect. Try again

Question 44

The was find the average (mean)
1) Find the mean of the following data set:

69, 2, 7, 10, 28, 21, 16, 40, 86

(your incorrect answer) a) 21
Incorrect.

The correct answer is b. (69+2+7+10+28+21+16+40+86)÷9=279279÷9=31
b) 31
c) 44
d) 86

Question 45

Trick question “lasted less”
2. Based on the following box plot, what percent of initial client consultations last less than 70 minutes?

Question 46

The is was quartile for that means 25%
3. Based on the box plot below, approximately what percent of salespeople represented in this data set have a total first quarter sales level less than 120?
c. 25%

Click here to select this answer

Correct. Looking at the box plot, Q1
is approximately 120. As we know 25% of the data falls below Q1, we can determine that 25% of the salespeople
represented in this data set will have a total first quarter sales level below 120.

Question 47

Read these carefully - Medium to Maximum
5. Based on the box plot below, what percent of the data falls between 83 and 88?
b. 50%

Click here to select this answer

Correct. We know that 50%
of the data represented in a box plot falls between the median and the maximum value.
In this box plot, 83 is the median and 88 is the maximum value. Therefore, 50% of the data values fall between these two values.

Question 48

A 3-year longitudinal study was conducted to investigate the approval ratings for the mayor of New City among registered voters.
In 2014 among 86,748 registered voters surveyed, 58,593 gave the mayor a favorable rating.
In 2015 among 82,523 registered voters surveyed, 52,931 gave the mayor a favorable rating.
In 2016 among 84,169 registered voters surveyed, 55,475

gave the mayor a favorable rating.

1. What type of variable is in this study?Categorical
   Quantitative
   Cannot be determined

Answer 48

Categorical

Question 49

Case Study
To solve this problem, we will work in steps.

Step 1: convert the net margin from percent to decimal.
The net margin in decimal form is:
Your response

.475
Suggested/Sample Response
The answer is 0.475
.
Since the net margin is given as a percent rather than as a decimal, we begin with converting it to a decimal.
Remember that to convert a percent to a decimal, you simply divide it by 100 to get 0.475
.
Step 2: set up an equation.

Next, we need to set up an equation. For this, remember that the net income and the net margin are defined as follows:

Net Income=Revenue−(Salaries and Benefits+Cost of Supplies+Other Expenses)

Net Margin=Net Income÷Revenue

Using the variable M

for the net margin and the other variable letters provided previously, we can rewrite these equations using variables:

N=R−(x+y+a)M=N÷R

In the above equations, we know the values for R
, x, y, and M, and we need to find a. We do not know the value for N, the net income, but we can substitute its equivalent expression from the first equation into the second equation. In other words, since we know that N equals R−(x+y+a), we can take its equivalent expression R−(x+y+a) and substitute it for N in the second equation M=N÷R

.
This gives the following new equation (fill in the missing variable letter):
M=N÷R=(R−(x+y+a))÷
________?

Answer 49

Your response

R
Suggested/Sample Response
The answer is R
.
After substituting (R−(x+y+a)), the expression is:
M=N÷R=(R−(x+y+a))÷R

Step 3: substitute known values

We can now substitute the variables with their known values, distribute the negative sign before the parentheses, and combine like terms using the following formula:

M=(R−(x+y+a))÷R

Please enter the equation substituting for known variables in the box below.
Your response

RM = -Rx + Ry + Ra
Suggested/Sample Response
The answer is:
0.475=(60,000,000−(15,500,000+8,500,000+a))÷60,000,000
.
Remember to use the decimal form of 47.5%.
Substitute:
60,000,000 for R
15,500,000 for x
8,500,000 for y.
The resulting equation is:
0.475=(60,000,000−(15,500,000+8,500,000+a))÷60,000,000
.

Step 4: solve the equation
Now, we can use the multiplication principle of equality to multiply both sides by $60,000,000
and simplify, then use the subtraction principle of equality to isolate on one side of the equation: (Do not enter the $ sign in your answer.)
Your response

249000000
Suggested/Sample Response
The answer is 7,500,000
.
0.475⋅$60,000,000=($36,000,000−a)÷$60,000,000⋅$60,000,000
Multiply $60,000,000 by 0.475; The $60,000,000 cancel each other out, so the equation now becomes:
$28,500,000=$36,000,000−a
Subtract $36,000,000 from both sides to isolate the variable:
$28,500,000−($36,000,000)=$36,000,000−a−($36,000,000)
The equation now becomes:
−$7,500,000=−a
Finally, multiply both sides by −1 to find the value of positive a:
a=$7,500,000

Question 50

A 3-year longitudinal study was conducted to investigate the approval ratings for the mayor of New City among registered voters.
In 2014 among 86,748 registered voters surveyed, 58,593 gave the mayor a favorable rating.
In 2015 among 82,523 registered voters surveyed, 52,931 gave the mayor a favorable rating.
In 2016 among 84,169 registered voters surveyed, 55,475

gave the mayor a favorable rating.
2. What type of chart(s) would be best to display this data?

A bar chart
A stem plot
Either a or b
None of the Above

Answer 50

a is correct
×
The answer is a. A bar chart would be good choice because the data to display is categorical.

Me:Wait I though bar charts are quantitative?
Copilot:While bar charts are typically used for categorical data, they can be used for quantitative data in certain contexts. For example, if you want to compare discrete quantities of different categories, like the number of sales in different months, a bar chart can be useful. However, if you’re dealing with continuous quantitative data, line charts or histograms might be more appropriate.

Question 51

A market research study asked people how much income their family makes each month. The results were summarized in the table below:
Household Monthly Income Frequency
Less than $ 2,000
6
$ 2,001 to $ 3,000
16
$ 3,001 to $ 4,000
22
$ 4,001 to $ 5,000
18
$ 5,001to $ 6,000
16
$ 6,001 to $ 7,000
5
Greater than $ 7,001
5

3. What type of variable is in this study?Categorical
   Quantitative
   Cannot be determined

Answer 51

b is correct
×
The answer is b. A histogram is a graphical display that displays continuous data such as provided in the table.

Quantitative

Me: This not a pies chart or a bar chart
Copilot: bar chart???

Question 52

5. A study was conducted on the number of attendees each day at the state fair.
   You are asked to recommend a method for displaying the data graphically so that the shape of the data can be seen,
   and each data value is also visible. What would be the best choice among the following? (Enter the letter that corresponds
   with your choice.)

a. Bar chart
b. Histogram
c. Scatterplot
d. Stem plot

Answer 52

Stem Plot

Stem plot is the best choice as these types of graphs show the shape of a data set and each data value.

Copilot: A stem plot (or stem-and-leaf plot) is a method that allows you to see the shape of the data distribution while preserving the actual data values. Each value is divided into a “stem” (the leading digit(s)) and a “leaf” (the last digit). This makes it easy to see the overall distribution and patterns in the data.

Question 53

You are a professional trainer at a local sports academy. You ask your athletes to determine the number of grams of protein they consume for a particular meal. Which of the following would be the best choice to illustrate the shape of the data you collect?

a) Bar chart
b) Pie chart
c) Box plot
d) None of the above

Answer 53

Box plot

Feedback: The correct answer is c. As the data you are collecting is quantitative data,
from the choices below a box plot would be your best choice to illustrate the shape of the data.

Question 54

Use the pie chart to answer the following question.

If 200 people are surveyed, how many claim to have had no exercise? Pie chart reflecting the average number of hours exercised per week. No exercise 36%, 1 - 2 hours 28%, 3 - 4 hours 12%, 4 - 5 hours 10%, 5 - 6 hours 8%, 6 - 7 hours 4%, more than 7 hours 2%.

a) 18
b) 36
c) 72
d) Cannot determine

Feedback: The correct answer is c. 200×0.36=72

Answer 54

c) 72

Feedback: The correct answer is c. 200×0.36=72

Question 55

Range is equal to the difference between the minimum and maximum value in a given measurable set
Determine the range for the following data set. {1,24,26,28,32,36,38,40,65}

a) 1 to 65
b) 64
c) 65
d) Cannot determine

Answer 55

Feedback: The correct answer is b. Range is equal to the difference between the minimum and maximum value in a given measurable set. The maximum value of this set is 65. The minimum value is 1. Therefore, range for this data set is 64.

b) 64

Question 56

Number of Pop Tarts in a box

Weight of each Pop Tart

Number of calories per flavor

Cost of a single Pop Tart

Time to toast a Pop Tart

Answer 56

Quantitative Data

Question 57

Flavors (e.g., Strawberry, Blueberry)

Frosting types (e.g., Frosted, Unfrosted, sprinkes)

Filling types (e.g., Jam, Chocolate)

Packaging colors (e.g., Blue, Red)

Special editions (e.g., Holiday-themed)

Answer 57

Qualitative(Categorical) Data

Question 58

What would be the best type of graph to use to display the age of all employees in a particular division in a company?

a) Bar chart
b) Histogram
c) Scatterplot
d) Pie chart

Answer 58

b) Histogram

Feedback: The correct answer is b. This is quantitative data that will be grouped into ranges or bins. Therefore, a histogram is the best choice to display this data.

Question 59

Bar chart -
Vertical—> info Ice creams 0 -70
hiorizontal –> Mond + 70 , Tues + 68 , Wed= 55 Thrus 40, Fri, ssat, sun ect,.
Bar Chart reflecting the average number of ice creams sold on each day of the week. Mon. 70, Tue between 60 and 70, Wed. between 50 and 60, Thur. between 40 and 50, Fri. between 60 and 70, Sat between 30 and 40, Sun. 30.
What type of data is presented in this chart?

a) Categorical
b) Quantitative
c) Numerical
d) Both b and c

Answer 59

a) Categorical

Feedback: The correct answer is a. This data is categorical as it is grouped into categories. (ie. days of the week).

Question 60

More on deviation
On average, Lightning Communications delivers to their customers, high-speed Internet connections of 70 Mbps, with a standard deviation of 12 Mbps. About what percentage of customers will experience a network speed between 70.0 Mbps and 94.0

Mbps? Assume a normal distribution.

a) 68%
b) 34%
c) 47.5%
d) 49.85%

Answer 60

c) 47.5%

Feedback: The correct answer is c. The Standard Deviation Rule says that 95%
of the values will fall within 2 standard deviations of the mean. Since we are looking for the amount that falls 2 standard deviations above the mean,
we can divide this number in half to find the percentage. Therefore, 47.5% will fall within 2 standard deviations above the mean.

Question 61

How are the mean and median of a sample related if the distribution is negatively skewed?

a) The mean is greater than the median.
b) The mean is less than the median.
c) They are equal.
d) Cannot be determined

Answer 61

b) The mean is less than the median.

Feedback: The correct answer is b. When the distribution is negatively skewed, the mean is less than the median.

Question 62

You surveyed 50 IT analysts in the Boston area to determine at which tech firm they are employed. What type of graph would be best to use to display this data?

a) Bar graph
b) Pie chart
c) Histogram
d) Dot plot

Answer 62

a) Bar graph

Feedback: The correct answer is a. Bar graph. While pie charts are used for categorical data,
a bar graph is a better choice since the entire population of IT analysts in Boston has not been surveyed.
The best way to display a large quantitative data set is a histogram.

Question 63

another standard deviation one
The mean salary of an entry-level financial analyst in Anytown is $ 65,300 and the standard deviation is $ 11,300. What values would 95%

of the data fall between? Assume a normal distribution.

a) $ 47,200 and $ 89,700
b) $ 42,200 and $ 86,000
c) $ 42,700 and $ 87,900

Answer 63

c) $ 42,700

The answer is c. Use the Empirical Rule to determine that 95%

of the starting salary values will be within two standard deviations of the mean.

Therefore, the upper limit will be:

65,300+2(11,300)=65,300+22,600=87,900

And the lower limit will be:

65,300−2(11,300)=65,300−22,600=42,700

Therefore, 95%
of the salary levels will be between $ 42,700 and $ 87,900.

Question 64

Which of the following would be the best option to graphically display continuous data?
a) Bar Chart
b) Histogram
c) Pie Chart
d) Box Plot

Answer 64

The answer is b. A histogram is a graph that displays continuous data. Histograms measure how
continuous data is distributed over various ranges.

Question 65

About 95 percent of results in a normal distribution fall between one standard deviation below the mean and one standard deviation above the mean. True or False?
a) True
b) False

Answer 65

The answer is b. This is a false statement. According to The Empirical Rule, approximately 68%
of the data points in a dataset will be within 1 standard deviation of the mean. 95% of all values are within 2 standard deviations of the mean.

Question 66

Another standard deviation one
8) Which of the following best describes a measure of spread?
a) Day of the week with the most librarians on staff at BMC Library.
b) The average number of books on a bookshelf in the Reference section of the library of a random sample of 15 bookshelves.
c) Number of books put on reserve by library patrons in 2014
d) Range of pages for volumes in an Encyclopedia complete volume set.

Answer 66

d) Range of pages for volumes in an Encyclopedia complete volume set.

Range is one example of a measure of spread.

Question 67

Know explanatory vs response variable

                            Outside Connection     Type
	                Safe Connection	          Suspicious Connection Server Type:Web Server	   60                     23 Server Type:Email Server   67                         6 

3. Name the explanatory variable.

Answer 67

Server Type is the explanatory variable.

Question 68

Which variable, explanatory or response, is displayed on the x-axis on side-by-side boxplots?

Answer 68

Side-by-side boxplots can be horizontal or vertical, so either variable (explanatory or response) can be displayed on the x-axis.

Question 69

10. A network security firm is hired by a small finance company to perform comprehensive information security services. As part of the service, the security manager analyzes the network security settings versus the login errors received from illegitimate users. The security manager is interested in deciphering the relationship between the network segment’s security level (safe or unsafe) and the number of illegitimate user login errors. For this analysis: (for the following questions enter the letter that corresponds with your answer)
    a. Which of the following is the explanatory variable?Network segment
    Network security level
    Illegitimate user login errors
    Network encryption

Answer 69

The explanatory variable is network encryption.

Question 70

In a two-way table, which best describes the sum of all of the joint frequencies?

a) The total number of individuals in the study.
b) The marginal frequency.
c) The correlation coefficient (r).
d) The total number of individuals in the treatment group.

Answer 70

a) The total number of individuals in the study.

The correct answer is a. In a two-way table, the sum of all of the joint frequencies is equal to the total number of individuals in the study.

Joint frequencies total number of individual in study

Question 71

Categorical vs Qualitative again
When can two-way tables be used?

a) When both the explanatory and response variables are quantitative.
b) When both the explanatory and response variables are categorical.
c) When one variable is categorical and the other variable is quantitative.
d) Two-way tables are used regardless of whether the variables are categorical or quantitative.

Answer 71

b) When both the explanatory and response variables are categorical.

The correct answer is B. Two-way tables are used when both the explanatory and response variables are categorical.

Question 72

7. True or False? A scatterplot always shows the explanatory variable on the horizontal, or x-axis.
   a. True
   b. False

Answer 72

A is correct
×
Correct. This is a true statement. A scatterplot always shows the explanatory variable on the horizontal, or x-axis.

Question 73

Know your terms “ Strong”
Negative Linear Correlation
Suggested/Sample Response
The overall pattern is moderately strong, negative, and linear.

Question 74

Describe the form of the relationship; is it linear, curvilinear, or is there no association? Please type in the response that corresponds with your answer.
Question 5.

Answer 74

Outlier made this liner

Question 75

8. How strong is the relationship? Is it weak, moderate, or strong? Please type in the response that corresponds with your answer.

Question 76

Both variable measure quantitative data

Question 77

1. CableNow, an Internet and cable TV provider company, is conducting a customer satisfaction survey on TV cable installation services. The company sends an email to all customers with a link to the survey and an offer to receive a discount on the next month’s bill.

Based on the information given, is there any potential bias in this study?

Answer 77

a. Yes, because the sampling frame does not match the intended population.

Correct. The answer is a. The company sent out a survey to all customers,
including those who did NOT receive the service. Therefore, the sampling frame is not
representative of the intended population — the customers who recently received installation services.
The sampling method (voluntary) may also be a cause of bias because portions of the intended population
may not be represented.

Question 78

What can be inferred from the data in the number of units produced vs. production costs?

a) There is a causal relationship between the number of units produced and production costs.
b) There is a negative association between the number of units produced and production costs.
c) There is no association between the number of units produced and production costs.
d) There is a positive association between the number of units produced and production costs.

Answer 78

d is correct
×
The answer is d. From the scatterplot, it can be determined that there is a positive association between the number of units produced and costs.
It cannot be determined if there is a causal relationship between the number of units produced and costs.

I answered Causal relationship

Question 79

Based on the information in this scatterplot, a lower household income causes a higher incidence of homicide. True or false?

Answer 79

This is a false statement. We cannot conclude causation from a scatterplot alone. We would need to confirm that the data was generated from a well-designed experiment.

Question 80

No. Simplson’s Paradox can ocur
False is correct
×
This statement is false. When Simpson’s Paradox occurs, a trend that appears in groups of data disappears once the groups are combined

Answer 80

No. Simplson’s Paradox can occur
False is correct
×
This statement is false. When Simpson’s Paradox occurs, a trend that appears in groups of data disappears once the groups are combined

Question 81

Consider the data in the table above. Will a Simpson’s Paradox be evident, with respect to the relative acceptance rates of males and females? Why or why not?

a) No, because there are an equal number of applicants for each College.
b) Yes, because there are different numbers of applicants for each College.
c) Yes, because the acceptance rates were different for each College.
d) Cannot be determined given this information.

Answer 81

I answered yes…different number of applicants

a is correct
×
The answer is a. No, because the trend that females have a greater acceptance rate at each of the Colleges remains
when the overall acceptance rate for all of the Colleges is calculated, we do not see Simpson’s Paradox occurring here.
This was expected because an equal number of male and female applicants are in each group.

Question 82

I just like this one&raquo_space;.
10. Overall we identified that Prep Course A is more effective than Prep Course B at preparing students to pass the certification exam. What lurking variable would make you question this result?

No Simpson's paradox is evident, therefore there is no lurking variable
The students taking Prep Course A in Cohort 1
The people taking Prep Course B in Cohort 1
Which cohort a student was in
-
d  is correct × The answer is d. Considering which cohort a student was in would lead you to conclude that Prep Course B was more effective  than Prep Course A. As a result,  this is the lurking variable associated with Simpson's paradox in this case.

Question 83

Response vs Explanatory
5. How does net profit margin depend on price?

Answer 83

Explanatory

Question 84

Complete the following sentence. Regression analysis is used to _________________.

calculate the probability that an event will occur.
determine if there is an association between two or more variables.
predict future values based on known values.
determine a cause and effect relationship between two or more values.

Answer 84

c is correct
×
The answer is c. Regression is used to describe a trend or predict future values based on known values.

I answered every option

Question 85

Answer two wrong - better understand this Module 6: Correlation & Regression
From the scatterplot below, if the trend line would be extended indefinitely, it would correspond with a factory production capacity in excess of 100

%. What pitfall in regression analysis is evident in this chart?
A graph that illustrates the effect of units produced on a factory’s production capacity. The points on the scatterplot and the line of best fit move slightly up and to the right.

a) Inappropriate Extrapolation
b)Association is Not Causation
c) Not a Representative Sample
d) Small Sample Size

Answer 85

a is correct
×
The answer is a. It is obvious that the production capacity of a factory can not exceed 100%,
so therefore it would be inappropriate to extrapolate beyond this range.
This analysis suffers from inappropriate extrapolation.

Question 86

Go this right just compare above
6. Analysis of the scatterplot below suggests that as the price of gas per gallon increased, presidential approval rating decreased.
What problem in regression is evident in this analysis?

Answer 86

b is correct
×
The answer is b. This analysis is obviously missing a lurking variable which, in this case,
might be party affiliation or other actions and decisions made by the president.
It is nonsense to try to estimate the approval rating for a president based on the price per gallon of gas alone.
Therefore, the association is not a causation.

Question 87

Answered Random Missing Data
9. What factor is most important to obtain a correct conclusion when performing regression analysis?
The answer is b. The greater the sample size, the more likely you are to come to a correct conclusion.

Question 88

(3 wrong on this one - orig. answ. obtain new sample)
Through what method can you identify if missing data is skewing the results of the study?

a) Obtain basic statistics for the entire population and compare those with the sample being studied.
b Perform regression analysis for every subgroup of the sample being studied.
c) Obtain a new sample of study subjects and compare the results with the original sample.
d) Reduce the sample size to ensure less variation across the study population.

Answer 88

a is correct
×
The answer is a. While it is difficult to identify if missing data is skewing the results of the study,
one approach is to obtain basic statistics for the entire population and compare those with the sample being studied

Question 89

Not make sense to use scatterplot shit!!
4) Continuing with the Anytown Power Co. example, from Question 2 and 3:

Anytown Power Co. is looking at the relationship between the daily high temperature in Anytown and the increase in power demand. The following graph shows this relationship:
How would you use this scatterplot to predict the increase in power demand in Anytown that would occur on a 35-degree day?

a) Using the regression equation, you would plug in the temperature (35) for x.
b) It would not make sense to use this scatterplot, as that would be inappropriate extrapolation beyond the range of study.
c) Take the percentage increase in power demand on a 70-degree day, and divide this total by 2
d) Using the regression equation, you would plug in the temperature (35) for y.

Answer 89

The correct answer is b. It would not make sense to use this scatterplot to predict the increase in power demand in Anytown that would occur on a 35
-degree day, as that would be inappropriate extrapolation beyond the range of the data in this graph.

Question 90

You need to study this page “ 6.08 Potential Problems in Regression Analysi”

Question 91

Nope
1) Which of the following needs to be true to perform a linear regression analysis?

a) All points need to fall exactly on the regression line.
b) There needs to be a causal relationship between the two variables.
c) There needs to be a linear relationship between the two variables.
d) None of the above.

Answer 91

The correct answer is c. To perform a linear regression analysis, there needs to be a linear relationship between the two variables. Otherwise, there can be no effective “line of best fit” to model the relationship.

Question 92

A strong correlation always explains a cause-and-effect relationship between two variables. True or False?

Answer 92

b is correct
×
This statement is false. A correlation does not prove that one variable causes another.
It is possible that both of the variables in question are affected by some other factor,
or that one variable is a subset of the other.

Question 93

In addition to measuring linear relationships, the correlation coefficient can be used to measure curvilinear and parabolic relationships.
True or False?

Answer 93

This statement is false. The correlation coefficient measures if two variables have a linear relationship with one another.

Question 94

Estimate the correlation coefficient for the scatterplot in question #5.

−0.92
−0.1
0.5
0.92

Answer 94

a is correct
×
The answer is a. Weak correlations have correlation coefficients close to 0
. Because this is a strong negative correlation, the correlation coefficient is negative and close to −1, so it can be estimated to be around −0.92.

close no cigar

Question 95

T more blob-y and up to the right
Which of the following scatterplots is most likely to have a correlation coefficient of 0.4:

Answer 95

The correct answer is a. This scatterplot shows a positive, moderate correlation, that might have a correlation coefficient of 0.4.

Question 96

For adults aged 20 and older, running speed and age have a negative correlation. Which of the following best describes the relationship between these two measures?
a) Older people run slower.
b) Younger people run faster.
c) As age increases, the speed at which someone runs decreases.
d) All of the above.

Answer 96

d) All of the above.
all of the above blah

The correct answer is d. All of the above. All of these statements are true because there is a negative correlation between these two variables.

Question 97

If a hypothesis test yields a result that 85% of the results did not occur by chance, what is the p

-value of this study?

a.) 0.08
b.)0.15
c.)0.58
d.)0.85

Answer 97

b is correct
×
If 85%
of results did not occur by chance, therefore, 15% of the results occurred by chance and the p-value for this study is 0.15.

Question 98

An event with a probability of 9/20 .

Answer 98

b is correct
×
The answer is as likely as unlikely. 9/20=0.45
, which means the event is as likely as unlikely.

Question 99

An experiment is the procedure to test the occurrence of an event.

True or False?

Answer 99

b. False

Correct. This is a false statement. An experiment is the procedure for which the probability of an event is calculated.

Question 100

You examine the number of times a player hit a home run this season, divided by the number of at-bats the player had. What is this an example of?
a) Theoretical Probability
b) Empirical Probability
c) The Law of Large Numbers
d) All of the above

Answer 100

b) Empirical Probability

The answer is b. We are using the number of times an event occurred to estimate the probability, therefore this is an example of empirical probability.

Question 101

What is the size of the sample space for flipping 3 coins?

Heads, Heads, Heads
Heads, Heads, Tails
Heads, Tails, Heads
Heads, Tails, Tails
Tails, Tails, Tails
Tails, Tails, Heads
Tails, Heads, Tails
Tails, Heads, Heads

Answer 101

8 is correct
×
The answer is 8
. From the list constructed below, there are 8 outcomes.

Question 102

What is the probability of an even number and tails?1/4

Answer 102

1/4

Question 103

What is the probability of a number greater than or equal to 8?

Answer 103

3/10

Question 104

What is the probability that you do NOT win both rounds of rocks-paper-scissors-shoot?

a) 1/4
b) 1/2
c) 3/4
d) 1

Answer 104

The answer is c. There are four equally likely outcomes. Three of those outcomes do NOT involve you winning both rounds. Therefore, the probability is 3/4

Read the questions

Question 105

What is the probability that a 10-sided fair die shows a multiple of 3 or 10?

Answer 105

The answer is 25. There are 3 multiples of 3 (3, 6, 9) and one value of 10. The probability is 310+110=410=25 .

Question 106

Out of class 20 students, what is the probability that you or your 3 friends are picked first?

Answer 106

1/5
READ THE QUESTION “ YOU AND FRIENDS”

Question 107

Out of class 20 students, what is the probability that you or your 3 friends are picked first?
Independent or Dependent?

Answer 107

Dependent

Question 108

Out of class 20 students, what is the probability that you or your 3 friends are picked first?
Independent or Dependent?

Answer 108

Dependent

Question 109

The probability of getting lung cancer given a history of smoking.
Independent or Dependent?

Answer 109

Dependent

Question 110

The probability of flipping a coin and getting three heads in a row, given an initial flip of heads.
Independent or Dependent?

Answer 110

Dependent

Question 111

Relative frequency helps determine if an event is independent. True or False?

a. True
b. False

Answer 111

a. True
Correct. This is a true statement. The relative frequency is related to the independence of events.

Question 112

Rolling a 6 on the first roll and rolling a 6 on the second roll.
Rolling a 6 on the first roll and rolling a 6 on the second roll

Independent or Dependent?

Answer 112

Independent

Question 113

If the first card drawn is red and not put back into the deck, then what is the probability the second card drawn is also red?

Answer 113

25/51

Question 114

There are 52 cards in a deck of cards.
If the first card drawn is a heart and not returned to the deck, then what is the probability the second card drawn is also a heart?

Answer 114

4/17

Question 115

Which of the following formulas should be used to solve for P(B|A)?

P(B|A)=P(A)×P(B)
P(B|A)=P(A)+P(B)
P(B|A)=P(A and B)×P(A)
P(B∣∣∣A)=P(A and B)P(A)

Answer 115

The formula for conditional probability is P(B∣∣A)=P(A and B)P(A)

Question 116

What is conditional probability?

Answer 116

Correct. The answer is c. Conditional probability is the probability of an event occurring given that another event has already occurred.

Question 117

For dependent events, the probability of B is always equal to the probability of B, given A. True or False?

Answer 117

b. False

Correct. For dependent events, the probability of B
is not equal to the probability of B, given A.

Question 118

Getting a toy lawnmower and a green item,
using P(B|A)=P(B).

Independent or Dependent?

Answer 118

independent is correct
×
The answer is independent. Let A=
getting a toy lawnmower. Let B= getting a green item. There are two lawnmowers,
and one of them is green. Therefore, P(B∣∣A)=12.
Meanwhile, the probability of choosing a green item is 12=6112.
Therefore, P(B|A)=P(B). According to this formula, the events are independent.

Question 119

Getting a toy lawnmower and a brown item,
using P(B|A)=P(B).

Independent or Dependent?

Answer 119

dependent is correct
×
The answer is dependent. Let A=
getting a toy lawnmower and B= getting a brown item. There are two lawnmowers, and one of them is brown. Therefore, P(B∣∣A)=12.
Meanwhile, the probability of choosing a brown item is 412=13. Since P(B|A)≠P(B), the events are dependent.

Question 120

Getting a beach ball and a green item,
using P(A and B)=P(A)×P(B).

Independent or Dependent?

Answer 120

independent is correct
×
The answer is independent. Let A = getting a beach ball. Let B = getting a green item. P(A and B) = 112 since there are 12 items and only 1 green beach ball. P(A) = 212 = 16. P(B) = 612 = 12. P(A) x P(B) = 16 x 12 = 112. Since P(A and B)=P(A)×P(B)
, the events are independent according to this formula.
2/12 is 0ne 6th

Question 121

10. Getting a hockey stick and a red item,
    using P(B|A)=P(B|not A).

Independent or Dependent?

Answer 121

independent is correct
×
The answer is independent. Let A=
getting a hockey stick and let B= getting a red item. P(B|A)=0 since there is only one hockey stick and it isn’t red. P(B|not A)=0,
as there are 11 non-hockey stick items, and none of them are red. Since 0=0, the events are independent.

Question 122

1. The probability of two independent events both occurring is P(A)+P(B). True or False?

Answer 122

Correct. This is a false statement. The probability of 2 independent events both occurring is P(A)×P(B).
(guessed)

Question 123

2. Which statement does not belong for two independent events?
   b. P(A|B)=P(B)

Answer 123

Correct. The answer is b. The correct statement is P(A|B)=P(A)
(guessed)

Question 124

The probability of the union of two dependent events is P(A)+P(B|A).

True or False?

Answer 124

Correct. This is a false statement. The probability is P(A)+P(B)−P(A
and B).

guessed

Question 125

Independence can be determined from any of the four given statements below:

P(A and B)=P(A)⋅P(B)

P(A|B)=P(A)
P(B|A)=P(B)
P(B|A)=P(B|not A)

True or False?

Answer 125

a. True

Correct. This is a true statement. Any of the four cases determine if the two events are independent

Question 126

5) A and B are independent events. P(A)=0.3 and P(B)=0.8. Calculate P(A|B)

a) 0.24
b) 0.3
c) 0.8
d) 1.1

Answer 126

b) 0.3

P(A|B)=P(A)=0.3

Question 127

A game has a 10-sided fair die. What is the probability of rolling an even number or a number less than 5?

a) 1/10
b) 3/10
c) 7/10
d) 9/10

Answer 127

c) 7/10

Feedback: The correct answer is c. The probability of an even number is 5/10 and rolling a number less than 5 is 4/10. There are 2 values that are even and less than 5 (2 and 4). The probability is 5/10+4/10−2/10=7/10

70%

Question 128

(Interested)
Four cards are chosen from a deck of 52 cards with replacement. A deck contains 13 cards each of spades, hearts, diamonds, and clubs. What is the probability that each of the four cards is a diamond?

a) 116
b) 1256
c) 128,561
d) 1456,976

Answer 128

b) 1256

The probability of one diamond is 1352 or 14.
Since there are 4 cards drawn, the probability is multiplied 4 times. Therefore,
(14)(14)(14)(14)=1256

Question 129

(Should have counted)
What is the sample size for choosing an odd number between 1
and 75, including the numbers 1 and 75?

a) 37
b) 38
c) 39
d) 40

Answer 129

b) 38

The odd numbers are 1, 3, 5, etc., up to 75. There are 38 odd numbers in the sample space, and the sample size is equal to 38.

Question 130

Use the diagram below to answer the following question. Venn diagram. Intersecting circles labeled A and B. Circle A is blue, Circle B is red.
There are high school students that are in sports (A) and in band (B). What does A and not B represent?

a) Sports only
b) Band only
c) Both sports and band
d) Neither sports nor band.

Answer 130

a) Sports only

A and not B means only in sports and not in band. Therefore, the students are only in sport

Question 131

There are black, blue, and white marbles in a bag. Two marbles are drawn, one after another, without replacement. The probability the first marble is black is 0.36. The probability the first marble is black and the second is white is 0.27.
To the nearest hundredth, what is the probability of the second marble being white if the first marble chosen is black?

a) 0.27
b) 0.39
c) 0.75
d) 0.86

Answer 131

c) 0.75
Use P(B∣∣∣A)=P(A and B)P(A).
The probability of black and white is divided by the probability of black. Therefore,
0.270.36=

Question 132

A survey on favorite pizza topping was given:
33% said cheese was their favorite topping, 25% said pepperoni, 15% said sausage, and 27% said other. If two people are picked at random and replaced, what is the probability of picking two people that like cheese? Round your answer to a whole number.

a) 0%
b) 11%
c) 33%
d) 66%

Answer 132

11%

Feedback: The correct answer is b. The probability is 0.33
for cheese. Since there are 2 people, the probability is multiplied twice. Therefore, (0.33)(0.33)=0.1089=11%

Question 133

There are 10 blue, 10 red, and 10 green labels in a bag. The labels are drawn from the bag and not replaced. What is the probability of drawing a blue first, and not blue second to the nearest percent?

a) 22%
b) 23%
c) 32%
d) 33%

Answer 133

b) 23%

The probability of blue is fraction begin. 1030
or 13. The probability for not blue second is 2029. The probabilities are multiplied together. Therefore, (13)(2029)=0.2298=0.23=23%

Question 134

(Can be determined)
A sample space consists of 3 disjoint events. If one has a probability of 12 and another has a probability of 13, what is the probability of the third event?

Answer 134

1/6

Question 135

(Just did not follow thru)
There are 4 yellow and 6 red balloons in a bunch that an employee is handing out to children coming into a store. If the balloons are chosen randomly, what is the probability that the next two children are given yellow balloons?

Answer 135

.13 ?

Question 136

Flipping a coin and getting “heads” does not mean you are more likely to flip a “tails” on the next coin toss. What property of these two events makes this fact true?

Answer 136

The correct answer is d.
Two events that are independent means that the first event does not affect the outcome or probability of the second

Question 137

If tomorrow there is a 40% chance of rain and a 60% chance the Red Sox (the Major League Baseball team from Boston) will lose, what is the probability that a Bostonian watches a game in the rain in which the hometown team loses?
(Assume that the rain does not influence the outcome of the game)

Answer 137

The correct answer is d. A and B are independent events.
P(A and B) = P(A) x P(B) = .40 x .60 = .24, or 24%.

Question 138

(This one uses the add decimal then subtract multiple method)

If there is an 80% chance that her best friend will call her and a 35% chance her boyfriend will call her, what is the probability that Sheri receives a call from at least one of these 2 people?
(Assume that getting one call does not change the likelihood of a second call)

Answer 138

The correct answer is c.
This is an “or” probability problem.
P(best friend calling) + P(boyfriend calling) - P(both calling) = .8 + .35 -.28 = .87.

Question 139

What is the correct line graph for y = −2x + 9?
Do Rise and Run.
You go this wrong.

Answer 139

Rise: The vertical change between two points on the line (the difference in the y-coordinates).

Run: The horizontal change between two points on the line (the difference in the x-coordinates).

For example, if you have two points on the line:
(𝑥1,𝑦1) and (𝑥2,𝑦2), the slope 𝑚 is calculated by:

𝑚= (𝑦2−𝑦1)
(𝑥2−𝑥1)

Question 140

A normally distributed data set has a mean of 25 and a standard deviation of 2.
Which percentage of the data falls between 23 and 25?

34.0
68.0
95.0
99.7

Answer 140

34.0

Question 141

The bar chart below summarizes the final grade distribution for a statistics course:

Which percentage of students earned a B in the statistics course?

9%
22.5%
27.5%
40%

Answer 141

22.5%

Question 142

Which statement is true regarding the distribution of the histogram below?

7889998877666554332221111000 —->

The mean of the distribution is greater than its median.
The median of the distribution is greater than its mean.
The mean and the median of the distribution are equal.
The relationship between the mean and the median cannot be determined from the histogram.

Answer 142

The mean of the distribution is greater than its median.

Question 143

A company has 14 employees. Six employees work day shift, five employees work swing shift, and three employees work night shift.

Which type of graph should be used to display how many employees work each shift?

Stem plot
Bar graph
Box plot
Histogram

Answer 143

Bar graph

Question 144

The chart below shows the population of Texas from 1900 through 2000 (in millions of people):
Why is this graph a misleading representation of this data?

Rounding to the nearest million distorts the true values.
The horizontal scale is uneven.
The vertical scale is uneven.
The x-axis and y-axis should be reversed.

Answer 144

The horizontal scale is uneven.

Question 145

A researcher is examining the relationship between the number of hours of sleep and score on a cognitive test.

Which method should be used to measure the linear relationship between these two variables?

Correlation
Proportion
Quartile
Standard deviation

Answer 145

Correlation

Question 146

A study is conducted on the possible relationship between the number of new car purchases and national unemployment rates.

Which numerical measure is appropriate for this situation?

Standard deviation
Five-number summary
Correlation coefficient
Conditional percentages

Answer 146

Correlation coefficient

Question 147

The percentage of drivers born before and after 1990 who can and cannot drive manual transmission is recorded in the table below:

Results Can Drive Manual Cannot Drive Manual Total
Before 1990 78% 22% 100%
After 1990 16% 84% 100%

What is the relationship between the time period drivers were born in and the ability to drive a manual transmission car?

*People born before 1990 are more likely to be able to drive a manual transmission car than people born after 1990 because 78% is greater than 16%.
*People born after 1990 are less likely to be able to drive a manual transmission car than people born before 1990 because 22% is less than 78%.
*People born before 1990 are more likely to be able to drive a manual transmission car than people born after 1990 because 78% is greater than 22%.
*People born after 1990 are less likely to be able to drive a manual transmission car than people born before 1990 because 16% is less than 84%.

Answer 147

People born before 1990 are more likely to be able to drive a manual transmission car than people born after 1990 because 78% is greater than 16%.

Question 148

How will removal of the outlier affect the relationship between missed work days and health rating in the scatterplot below?

(Hint: Is is a strong negative correlation)

It will weaken the positive relationship.
It will weaken the negative relationship.
It will strengthen the negative relationship.
It will strengthen the positive relationship.

Answer 148

It will strengthen the negative relationship.

Question 149

A researcher is trying to determine if promotions are based on gender. The researcher studies two companies and records the gender of the employees that received pay grade promotions during the last year.
The results are shown in the following table:
Female employees promoted Male employees promoted
Endothon Company 511/825 = 62% 89/108 = 82%
Quality Apple Farms 137/417 = 33% 131/375 = 35%
Total 648/1242 = 52% 220/483 = 46%
Is Simpson’s paradox evident in this data?

Yes, because while each of the companies promoted a higher percentage of male employees, overall a higher percentage of women were promoted
Yes, because the overall promotion rates were different
No, because a higher percentage of female employees were promoted by each company
No, because a higher percentage of male employees were promoted by each company

Answer 149

Yes, because while each of the companies promoted a higher percentage of male employees, overall a higher percentage of women were promoted.

Question 150

A coin has two sides: heads and tails.

If three coins are tossed, what is the probability of getting an odd number of heads?

3/8
5/8
1/2
1/4

Answer 150

1/2

Question 151

A fast-food company is interested in knowing the probability of whether a customer viewed an advertisement for their new special on the internet or on television. They found that 37% of customers saw the advertisement on the internet, 20% saw it on television, and 12% saw it on both the internet and on television.

What is the probability that a randomly selected customer saw the advertisement on the internet or on television?
Your

29%
45%
57%
69%

Answer 151

45%

Question 152

A marketing company chooses a survey participant among two respondents: one female and one male. The chosen participant is then asked to rate either product A, B, or C.

What is the probability that the respondent was male and rated product B?

0.167
0.333
0.500
0.833

Answer 152

0.167

Question 153

A company receives equipment from two factories: 38% from factory A, and all other equipment from factory B. Each factory has a percentage of equipment that is defective: 1% of factory A’s equipment is defective, while 4% of factory B’s equipment is defective.

If a piece of the company’s equipment is selected at random, what is the probability that it is defective and from factory B?

0.0248
0.0038
0.6012
0.6600

Answer 153

0.0248

Question 154

A box contains one red ball, one purple ball, and one blue ball. Two balls are drawn from the box one after the other without replacing the first ball.

How many outcomes are possible for this experiment?

3
6
9
10

Answer 154

6