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Statistics (OFFICIAL) Flashcards

1
Q

When computing the variance of a sample, the sum of the squared deviations, E (x-x)z,
is divided by?

A. The population size
B. The sample size minus one
C. The sample size
D. The population size minus one
E. None of the above
A

B. The sample size minus one

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2
Q

A company wants to graphically summarize in one chart the number of employees it
has in each of its five decisions. What type of chart would be appropriate for this
purpose?

A. Line chart
B. Box plot
C. Scatter diagram
D. Bar chart
E. None of the above
A

D. Bar chart

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3
Q

A manufacturer claims to have built a home stereo speaker that is 4 feet tall but uses an
average of only 30 watts of power. A sample of 40 speakers from the manufacturer
found that they used an average of 32 watts of power. The appropriate hypotheses to test
the manufacturer’s claim are?

A. Ho: M=30 versus HA:M=not equal30
B. Ho: M=32 versus HA: M=not equal32
C. Ho: M=30 versus HA:M=32
D. Ho: M=30 versus HA:M>30
E. None of the above
A

D. Ho: M=30 versus HA:M>30

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4
Q

If the alternative hypothesis states that the population mean is not equal to 3500, the
rejection region will consist of?

A. One region in the left tail (below 3500)
B. One region in the right tail (above 3500)
C. Two regions, one in the right tail and one in the left tail.
D. One region, centered about 3500.
E. None of the above.

A

C. Two regions, one in the right tail and one in the left tail.

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5
Q

A 98% confidence interval for a population proportion is determined to be 0.756 to
0.834. If the confidence level is reduced to 95%, the same data will produce an interval
that?
A. Is wider
B. Is narrower
C. Is the same
D. You cannot answer the questions without knowing the sample size.
E. None of the above.

A

B. Is narrower

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6
Q

If the correlation coefficient, r, is equal to one? R=1

A. The y-intercept must be equal to zero
B. The regression line goes through all the points and has a negative slope.
C. The standard error of the estimate, Sz is zero.
D. The slope of the regression line is one.
E. None of the above.

A

C. The standard error of the estimate, Sz is zero.

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7
Q
  1. The expected value of a random variable is also?
A. The median.
B. The mode
C. A weighted average
D. The variance
E. None of the above
A

C. A weighted average

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8
Q

A study if elementary schools in the Los Angeles Unified School District focused on
the percentage of teachers in each school with emergency credentials (x, in percent) and
the average reading scores (y) of fourth grade students in that school. The least squares
regression line was y=400-3x. If twenty percent of the teachers in prairie Elementary in
the San Fernando Valley have emergency credentials, you would expect the average
reading scores of the fourth grade students in prairie Elementary to be?

A. 60
B. 100
C. 340 
D. 399.4
E. None of the above
A

C. 340

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9
Q

Ten percent of the mail that arrives at a post office has insufficient postage attached. If
a postal worker selects 15 pieces of mail at random, what probability distribution should
he use to calculate the probability that three pieces of mail have sufficient postage?

A. Poisson
B. Exponential
C. Normal
D. Uniform
E. None of the above
A

E. None of the above

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10
Q

If the population is normal, the population standard deviation is known, and the
sample size is ten, which table would you use for calculating probability of the sample
mean?

A. Normal
B. Student t
C. Chi-square
D. Binomial
E. None of the above
A

A. Normal

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11
Q

If the null hypothesis is that the population mean is equal to 30 and you conduct a test
with a significance level of 0.05 and get a p-value of 0.08, then?

A. You must reject the null hypothesis
B. You are certain that the population mean is 30.
C. You cannot reject the null hypothesis.
D. The probability of type II error is 0.08
E. None of the above.

A

C. You cannot reject the null hypothesis.

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12
Q

A researcher has taken a random sample of more than two items. Compared with the
population standard deviation, the standard error of the mean is?
A. Larger than the population standard deviation.
B. Smaller than the population standard deviation.
C. The same as the population standard deviation.
D. Sometimes larger and sometimes smaller than the population standard deviation.
E. None of the above.

A

D. Sometimes larger and sometimes smaller than the population standard deviation.

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13
Q

A manufacturer of children’s toys claims that exactly 5% of all his producing are

defective. When 500 toys from today’s outputs were examined 0.8% were found to be
defective. The 500 toys is?

A. The parameter
B. The statistic
C. The population
D. The sample
E. None of the above.
A

D. The sample

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14
Q

A researchers is studying registered voters in Los Angeles to see if they favor the city
of Los Angeles being divided into boroughs (smaller governmental units within the
structure of the city). He asks 350 voters to tell him if they would vote for a plan that
would implement a borough system in Los Angeles. Out of the 350, 235 said they were
in favor of the plan. The population is?

A. The 235 voters in favor of the borough plan.
B. The 350 voters
C. All the voters in favor of the borough plan.
D. All the voters in Los Angeles
E. None of the above

A

D. All the voters in Los Angeles

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15
Q

A market researcher has interviewed 80 heads of house holds and recorded whether
the person was never married, divorced, windowed, or married. The data is?
A. Discrete
B. Continuous
C. Qualitative
D. Binomial
E. None of the above

A

C. Qualitative

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16
Q

A car dealer is studying his customers and the cars they buy. It is appropriate for him
to use a mean to describe?

A. The color of the car bought by a typical customer.
B. The zip code of a typical customer.
C. The mileage in miles per gallon of the car bought by a typical customer
D. The city of residence of the typical residence.
E. None of the above.

A

C. The mileage in miles per gallon of the car bought by a typical customer

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17
Q 
Given that a sample of 25 had E x=75, and E (x-x) squared =448, the mean and
standard deviation are?
A. x=3.0 and s=48/25
B. x=3.0 and s=48/24
C. x=3.0 and s=square root of 48/24
D. x=3.0 and s=square root of 48/25
E. None of the above
A

C. x=3.0 and s=square root of 48/24

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18
Q

A sample of dental offices found the numbers of cavities filled in the last week to be
as follows: 12, 4, 4, 12, 12, 10. The median number of cavities filled is?
A. 8
B. 9
C. 10
D. 11
E. 12

A

D. 11

4,4,10,12,12,12

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19
Q

Suppose that, in testing situation with a population that is normally distributed, the
null hypothesis is that the population mean is equal to 41. A sample of size 36 had a
sample mean of 41 and sample standard deviation of 2. Which of the following is
correct?

A. You should reject the null hypothesis
B. You are certain the population mean is 41
C. You cannot reject the null hypothesis
D. You must know the population standard deviation to complete the test
E. None of the above

A

C. You cannot reject the null hypothesis

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20
Q

Which of the following is ALWAYS true for test of hypothesis?

A. The null hypothesis contains
B. The null and alternative hypothesis are statements about the sample.
C. The alternative hypothesis is true
D. The null hypothesis is more likely to be true than the alternative
E. None of the above

A

E. None of the above

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21
Q

A sample of 100 receipts from a restaurant showed that 12 had errors. What is the
95% confidence interval for the proportion of all receipts that have error? Note that
20.025= 1.96 and t 0.025= 1.984 for 99 degrees of freedom?

A. 0.12 +- (1.96) square root of (0.12)(0.88)/100
B. 0.12 +- (1.984) square root of (0.12)(0.88)/100
C. 0.88 +- (1.96) square root of (0.12)(0.88)/100
D. 0.12+-(1.96) square root of (0.12)(0.5)/100
E. None of the above

A

A. 0.12 +- (1.96) square root of (0.12)(0.88)/100

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22
Q 
If you have data on product output and total cost of production, you can estimate
fixed and variable cost by using?
A. Bayes rule
B. Linear regression
C. A hypothesis test
D. A confidence interval
E. None of the above
A

B. Linear regression

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23
Q

The postal service has recently raised the price of a first class stamp by three cents to
37 cents. While you were in the post office, you saw 30 three cent stamps sold and 20 of
the new 37 cents stamps sold. What was the average price paid for a stamp while you
were in the post office?
A. 8.3 cents
B. 16.6 cents
C. 20 cents
D. 25 cents
E. none of the above

A

B. 16.6 cents

30 > 3 cents
20 > 37 cents

303=90
3720=740

740+90=830

30+20=50
830/50

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24
Q

An investor has purchased stock in a firm. The investor believes that , at the end of
the year, there is 0.10 probability that the stock will show a $6,000 profit, a 0.30
probability that the stock will show a $4000 profit and a 0.60 probability that the stock
will show a $2000 loss. The expected profit is $600. If the best profit increases by
$1000 from $6000 to $7000, the expected profit?
A. Will remain unchanged
B. Will increase by $10
C. Will increase by $100
D. Will increase by a $1000
E. None of the above

A

C. Will increase by $100

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25
Q 
The number of hours in the life time of a light bulb is a random variable of which
type?
A. Binomial
B. Poison
C. Continuos
D. Discrete
E. None of the above
A

C. Continuos

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26
Q

Which of the following in NOT an assumption that is required for the use of the binomial formula?

A. The trial are independent
B. The probability of success is the same for every trial
C. Each trial has only two possible outcomes
D. The random variable is the number of success out of N trials
E. All of the above assumptions are required

A

E. All of the above assumptions are required

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27
Q

A survey was conducted in July, 2002 of 200 of the 6000 CSUN business students. The survey asked the questions: Are you taking BUS 301 in the fall? Twenty percent of the 200 students said yes. Using this information?

A. The college knew exactly how many sections of BUS 301 to schedule
B. The College knew exactly how many how many sections of bus301 to schedule, but didn’t know how many should be at night C. The college knew the maximum number of section of bus 301 necessary
D. The college didn’t have enough information to be sure of hoe many sections to schedule
E. None of the abov

A

D. The college didn’t have enough information to be sure of hoe many sections to schedule

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28
Q

If a television rating service surveyed 800 viewers and 700 watched American Idol, the population is?

A. The 800 viewers surveyed B. The 700 viewers who watched American idol
C. The 100 viewers who did not watch American idol
D. All television viewers
E. None of the above

A

D. All television viewers

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29
Q 
You survey your friends and ask them which type of movie (action, comedy, romance, horror) they prefer.  Which of the following graphical displays would be most appropriate to display the data? 
A. Scatter diagram 
B. A least squares regression line 
C. A box plot 
D. A bar chart 
E. None of the above
A

D. A bar chart

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30
Q 
A car manufacturer states on the window sticker of its new cars: 38 MPG Highway.  This is an example of? 
A. A mean 
B. A proportion  
C. A standard deviation 
D. A range 
E. None of the above
A

B. proportion

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31
Q

A study of the number of cars sold looked at the number of cars sold at 500 Dealers The smallest dealer had 11 cars sold and the largest had 154 cars sold. If you were going to create a frequency distribution of the number of cars sold using six classes in your frequency distribution, which of the following might be a reasonable first class?

a. 0 to 25
b. 0 to 35
c. 5 to 35
d. 10 to 35
e. none of the above

A

(a) 0 to 25

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32
Q

Which of the following is always true for a test of a hypothesis?

(a) The type ll error is more important than type l error
(b) α is larger then β
(c ) α is the probability of a type ll error
(d) A type l error occurs when you accept the null hypothesis when it is not true
(e) None of the above is true.

A

(e) None of the above is true.

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33
Q

If you take a sample of size 24 from a normal population for which you do not know the population standard deviation and want to calculate a 95% confidence Interval for the mean, which is not need?

(c) The value of Z 0.224
(c) The value of Z 0.125
(c) The value of Z 0.025
(c) The value of Z 0.325

A

(c) The value of Z 0.025

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34
Q

The coefficient of determination, R² :

(a) Tell us how close the Regression line fits the points in a bar chart
(b) Tell us how close the Regression line fits the points in a scatter diagram.
(b) Tell us how close the Regression line fits the points in a graph

A

(b) Tell us how close the Regression line fits the points in a scatter diagram.

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35
Q

The retail price of a product is $5 per unit & the cost of production is $2 per unit. If the expected number of unit sold is 4, the expected profit will be

A

(b) 12

5 x 4 = 20
2 x 4 = 8
20 - 8 = 12

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36
Q

Is not assumption that is required for the use of binomial formula?

(a) The trails are independent (b) The probability of success is the same for every trail.
(c) Each trail has only 2 possible outcomes
(d) The random variable is the number of successes out of a trail
(e) All of the above.

A

(e) All of the above.

37
Q

You are measuring the life time of a light bulb. Which of the following might be
the distribution of this random variable:

(a) Binomial
(b) Normal
(c) Poisson
(d) All three
(e) None

A

(b) Normal

38
Q

If the P value is less then α, you :

(a) Should reject the null hypothesis.
(b) Should not reject the null hypothesis.

A

(a) Should reject the null hypothesis.

39
Q

Because of the variation in the measured contents of a can of cola:

(a) The average contents of a sample of 100 cans will give us the average contents for the day’s production of 100,000 cans.
(b) The average contents of a sample of 10 cans will give us the average contents for the day’s production of 100,000 cans.
(c) The average contents of a sample of 1,000 cans will give us the average contents for the day’s production of 100,000 cans.
(d) The average contents of a sample of 10,000 cans will give us the average contents for the day’s production of 100,000 cans.

A

(b) The average contents of a sample of 10 cans will give us the average contents for the day’s production of 100,000 cans.

40
Q

A manufacturer of children’s toy claims that exactly 5% of all his products are defective. When 500 toys from today’s output were examined, 8% were found to be defective. What is the parameter?

(b) The % of no toys made that are defective.
(b) The % of all the toys made that are defective.
(c) The % of some of the toys made that are defective.

A

(b) The % of all the toys made that are defective.

41
Q

X claims that the average box of X contains 12 ounces. You bought 1 box at each 5 different grocery stores. The weights were 13.1, 11.6, 12.1, 12.3 & 11.9 ounces. The mean weight of the 5 boxes was 12.2 ounces. The sample is – (5)

(a) 100
(b) 200
(c) 300
(d) 400
(e) None of the above.

A

(e) None of the above.

42
Q

A car manufacturer is studying the relationship between the weight of its vehicles and the mileage they get in city driving. Which following would an analyst for the company construct to aid in this study?

(b) The most squares regression line.
(b) The least squares regression line.
(b) Some squares regression line.

A

(b) The least squares regression line.

43
Q

Which of the following is NOT quantitative date?

(a) Whether a driver buys regular gasoline or not
(b) Whether a driver buys no gasoline or not
(c) Whether a driver buys premium gasoline or not

A

(c ) Whether a driver buys premium gasoline or not

44
Q

A basketball player scored 12, 25, 16, & 13 points in her last 4 games. What is the mean number of points per game she scored during this period?

A

(c) 16.5

12 + 25 + 16 + 13 = 66
66 / 4 = 16.5

45
Q

The sample 10, 18, 20 has a standard deviation of

(b) 4.29
(b) 5.29
(b) 6.29
(b) 7.29

A

(b) 5.29

[(36+4+16) ÷ 2] = 56 ÷ 2 = √28 = 5.29

46
Q

Which of the following is NOT one of the steps in hypothesis testing:

(a) Choose a probability for your type 2 error
(e) Choose a probability for your type 1 error
(e) Choose a probability with no errors
(e) All of the above
(e) None of the above.

A

(e) None of the above.

47
Q

An urban planner wished to determine whether there is sufficient evidence to conclude that the mean family income in the San Fernando Valley exceeds $38000. When the urban planner collects data on family incomes, he would –

(a) Use a one-tailed test with the alternative to the right (above $38000)
(b) Use a one-tailed test with the alternative to the left (above $38000)
(c) Use a one-tailed test with the alternative to the right (below $38000)

A

(a) Use a one-tailed test with the alternative to the right (above $38000)

48
Q

You took a sample of size 21 from a normal distribution with a known standard deviation, σ. In order to find a 90% confidence interval for the mean, You need to find.

(a) Then mean of the sample and the value of Z with an area of 10% in right tail.
(b) The value of Z with an area of 5% in the right tail, but not the sample mean.
(c) The mean of the sample and the value of Z with an area of 5% in the left tail.
(d) More information than given by any of a, b, or c.

A

(d) More information than given by any of a, b, or c.

49
Q

A study was conducted in Malibu on the value of a house (Y, in thousands of dollars) as it relates to the distance the house is from the beach (X, in miles). The result was the regression equation, Y= 800-20X. In the equation, the number 20 represents.

(c) For each extra mile a house is from the beach, the price drops by $50,00
(c) For each extra mile a house is from the beach, the price drops by $10,000
(c) For each extra mile a house is from the beach, the price drops by $20,000
(c) For each extra mile a house is from the beach, the price drops by $30,000

A

(c) For each extra mile a house is from the beach, the price drops by $20,000

50
Q

The probability distribution of Z is: X 1, 2, 3, 4 P(X) .30, .35, .20, .15 What is the expected number of children in a randomly selected Canadian household? Let X represent the number of children in Canadian household.

(b) 1.2
(b) 2.2
(b) 3.2
(b) 2.3

A

(b) 2.2

Expected Numbers. X and P(X) 
1*.30= .30 
2*.35=. .70 
3*.20= .60 
4*.15= .60

.30+.70=1.0
.60+.60=1.2
=2.2

51
Q

A sales representative make 3 in person visits to customers every morning. Out of the 3 visits, she will make either 0, 1.3 or 3 sales. The probabilities are 0.2, 0.4, 0.3, and 0.1, respectively. For each sale, she gets a commission of $100. Her expected commissions for one morning’s visits are:

(b) 120
(b) 130
(b) 140
(b) 150

A

(b) 130

52
Q

The binomial distribution is a distribution:

(a) Which is always symmetric
(b) Can always be used when sampling without replacement
(c) Which always takes integer values
(d) Which is always more spread out than the normal distribution
(e) None

A

(e) None

53
Q

A random variable is found by sampling classes at CSUN and counting the number of those classes with over 200 students enrolled. Which of the following distributions might be the distribution of this random variable.

(a) Random
(b) Normal
(c) Quantitative
(d) None of the above

A

(b) Normal

54
Q

For a given hypothesis test, the null hypothesis can be rejected at the 0.05 level of significance. We can infer that P-value.

A

(a) Is less than 0.05

55
Q

When you increase the size of your sample from a population:

(a) You decrease the population standard deviation
(b) You increase the standard deviation of the sample mean
(c) You decrease the standard deviation of the sample mean
(d) You decrease the sample standard deviation
(e) None

A

(c) You decrease the standard deviation of the sample mean

56
Q

A summary measure computed from a sample is a:

(a) Normal
(b) Statistic
(b) Random
(b) None of the above

A

(b) Statistic

57
Q

A manufacturer of children’s toys claims that exactly 5% of all his products are defective. When 500 toys from today’s output were examined, 8% were found to be defective. What is the sample?

(a) The 500 toys
(b) The 400 toys
(c) The 300 toys
(d) The 500 toys

A

(a) The 500 toys

58
Q

A student took a sample of 25 textbooks from the bookstore and recorded the costs of the books. The student wants to know whether the mean cost of all textbooks is greater than $75. The student should:

(A) Test the null hypothesis that the mean cost of all textbooks is equal to $0.
(B) Test the null hypothesis that the mean cost of all textbooks is equal to $25.
(C) Test the null hypothesis that the mean cost of all textbooks is equal to $50.
(D) Test the null hypothesis that the mean cost of all textbooks is equal to $75.
(E) None of the above

A

(D) Test the null hypothesis that the mean cost of all textbooks is equal to $75.

59
Q

Reasons to calculate the mean of a data set:

a. find range
b. find smaller number
c. find middle number
d. find measure of location

A

d. find measure of location

60
Q

Sample of dental cavities filled were 12, 4, 4, 12, 12, 10 what is median:

a. 8
b. 9
c. 11
d. 12
e. 10

A

c.11

61
Q

Ho: π= .6 H1: π >.6 sample is 250 p=.63 z=.97 sig.=.05 critic. z=1.64

a. reserve null hypothesis
b. reject null
c. accept alternative
d. conclude π> .6
e. none of above

A

e. none of above

62
Q

If alt. hypothesis states pop. Mean= 3500, rejection region will be…

a. right and left region
b. left and right region

A

c. left and right region

63
Q

Regression equation -1=5-2x, predicted value of y equals:

a. 1 when x=2
b. 2 when x=2
c. 5 when x=2
d. 2 when x=5
e. none

A

a. 1 when x=2

64
Q

There is a .20 probability that stock will profit 3000, .10 prob. That stock will profit 6000, .70 prob. -2000 losses. What is expected profit:

a. -2000
b. 2333
c. 2600
d. 3667
e. none

A

a. -2000

65
Q

The retail price of a product is $5 per unit & the cost of production is $2 per unit. If the expected number of unit sold is 4, the expected profit will be:

a. 8
b. 12
c. 20
d. 28
e. none

A

(b) 12

$5 profit per unit - $2 cost per unit = $3 * 4 unit sold = 12

66
Q

Which is NOT characteristic of normal distribution:

a. symmetric distribution
b. mean is 0
c. mean, median, mode is equal
d. distribution is bell shaped
e. all of the above

A

b. mean is 0

67
Q

If the P value is less then α, you :

(a) Should not reject the null hypothesis.
(b) Should reject the null hypothesis.

A

(b) Should reject the null hypothesis.

68
Q

Because of the variation in the measured contents of a can of cola, :

(a) The average contents of a sample of 10 cans will give us the average contents for the day’s production of 100,000 cans.
(b) The average contents of a sample of 10 cans will give us the average contents for the day’s production of 200,000 cans.

A

(a) The average contents of a sample of 10 cans will give us the average contents for the day’s production of 100,000 cans.

69
Q

A manufacturer of children’s toy claims that exactly 5% of all his products are defective. When 500 toys from today’s output were examined, 8% were found to be defective. What is the parameter?

(a) The # of all the toys made that are defective.
(b) The % of all the toys made that are defective.

A

(b) The % of all the toys made that are defective.

70
Q

X claims that the average box of X contains 12 ounces. You bought 1 box at each 5 different grocery stores. The weights were 13.1, 11.6, 12.1, 12.3 & 11.9 ounces. The mean weight of the 5 boxes was 12.2 ounces. The sample is – (5)

(a) All of the above
(b) None of the above

A

(b) None of the above

71
Q

A car manufacturer is studying the relationship between the weight of its vehicles and the mileage they get in city driving. Which following would an analyst for the company construct to aid in this study?

(a) The most squares regression line.
(b) The least squares regression line.

A

(b) The least squares regression line.

72
Q

Which of the following is NOT quantitative date?

(c ) Whether a driver buys premium gasoline or not

A

(c ) Whether a driver buys premium gasoline or not

73
Q

A basketball player scored 12, 25, 16, & 13 points in her last 4 games. What is the mean number of points per game she scored during this period?

A

16.5

12 + 25 + 16 + 13 = 66
66 / 4 = 16.5

74
Q

Which of the following is NOT one of the steps in hypothesis testing?

(a) Choose a probability for your type ll error.
(e) None of the above.

A

None of the above.

75
Q

Sampled 20 banks and recorded rates for 30 yrs. Data is:

a. discrete property that the number of possible values is either a finite number or a “countable” number, which results in 0 possibilities, or 1 possibility or 2 possibilities and so on.
b. continuous Result from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps, interruptions or jumps
c. qualitative - data that can be separated into different categories distinguished by some nonnumeric characteristic
d. binomial is an abstraction of the intuitive concept of chance into the theoretical domains of mathematics, forming the foundations o f probability theory and mathematical statistics

A

c. qualitative - data that can be separated into different categories distinguished by some nonnumeric characteristic

76
Q

Computing variance of sample sum of the square deviation is divided by

A

Population size minus one

77
Q

The distribution of home prices is often positively skewed (skewed to the right). In such a case, it is likely that
Select one:

a. the mean is equal to the median
b. the mean is greater than the median
c. the median is greater than the mean
d. the distribution will have two modes
e. none of the above

A

b. Mean greater than median

78
Q

Not a step in hypothesis testing:

(a) Calculate the sample Z-value
(b) Calculating the total

A

(a) Calculate the sample Z-value (test statistic)

79
Q

Which of the following statement is correct?

Expected value of a random variable is the long run average assuming the experiment is repeated many times.

A

Expected value of a random variable is the long run average assuming the experiment is repeated many times.

80
Q

The correlation coeffiect “r”

(a) Measure the relative relationship between 2 variable
(a) Measure the relative relationship between 1 variable
(a) Measure the relative relationship between 0 variable
(a) None of the above

A

(a) Measure the relative relationship between 2 variable

81
Q

Hypothesis test, the null hypothesis can be rejected at the 0.05 level of significance. We can conclude that the p-value:

(b) is more than 0.05
(b) is less than 0.05
(b) is equal than 0.05

A

(b) is less than 0.05

82
Q

Sample of 20 CSUN students found the age of each student:

(a) The highest age is at least twice the average age.
(b) The lowest age is at least twice the average age.

A

(a) The highest age is at least twice the average age.

83
Q

A care manufacturer states on the window sticker of its new care: 38 MPG highway. This is an example of:

(a) proportion
(b) mean

A

(a) proportion

84
Q

A manufacturer of children’s toys claims that exactly 5% of all his products are defective. When 500 toys from today’s output were examined, 8% were found to be defective. What is the population of interest?
Select one:

a. The 500 toys.
b. All the toys made today.
c. All the toys made by this manufacturer.
d. The 40 defective toys.
e. none of the above

A

c. All the toys made by this manufacturer.

85
Q

Top 15% of students get A. sample 4 from 200, to complete prob. That 2 of 4 got A’s, use:

a. binomial dist.
b. normal dist.
c. t dist. 3 degrees of freedom
d. t distribution with 199 degree.
e. none

A

Binomial distribution

86
Q

Standard deviation of population A is greater than the standard deviation of population B, all other things equal the confidence interval for the mean A should be:

a. Wider then the confidence interval for the mean of B
b. Narrower then B
c. Same width as the confidence interval for the mean of B
d. You can’t compare the width of the 2 interval without more info
e. None

A

(a ) Wider then the confidence interval for the mean of B

87
Q

a researcher is studying CSUN students. It is looking at all CSUN students of all ages what kind of data is this?

Polulation

A

Polulation

88
Q

To display a proportion of studying in each option of the BS in Business administration what would you use?

Pie chart

A

Pie chart

89
Q

A homeowner is interested in whether the thermostat on her heating system is working correctly (i.e., the temperature in the house will be what is set on the thermostat). She set the thermostat at 72 degrees and took 24 random temperature measurements in her house over a three day period. The alternative hypothesis about the temperature in the house should be
Select one:

a. the mean temperature is greater than 72
b. the mean temperature is equal to 72
c. the mean temperature is not equal to 72
d. the mean temperature is less than 72
e. none of the above

A

c. the mean temperature is not equal to 72

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