Chapter 6.2

Question 1

What is discrete data?

Answer 1

When the possible values are distinct and in-between values are not possible

e.g. whole numbers

pg. 337

Question 2

What is continuous data?

Answer 2

when possible values are any decimal

e.g. temperature

pg. 337

Question 3

What is the area of a graph?

Answer 3

-Continuous Distributions are represented by graphs
-Probability of an event will be the area
-sum of the probabilities for all the area must be 1

pg. 338

Question 4

How do you find area?

Answer 4

The total area must be 1
wXh=a
width divide height

e.g. 1=30h–h=1/30

pg. 339 & 340

Question 5

What is uniform distributions?

Answer 5

-continuous random variable that the likelihood of an occurrence is spread evenly
-a rectangular shape
-area must = 1 as area is = to probability

pg. 340

Question 6

What is normal distribution?

Answer 6

-a smoothed-out idealization of a histogram with normal distribution
-the peak is always the mean, mode and median
-symmetric with 50/50 split on each side

pg. 345, 346 & 347

Question 7

What is a z-score?

Answer 7

the number of SDs that the data value is above the mean
how far a data value is from the mean, relative to how spread out the data is
if above mean then z is positive
if below mean then z is negative

pg. 351

Question 8

What is the equation for z-scores?

Answer 8

z=(x-U)/@
z=(data value minus mu[mean])divided by sigma[SD]

To check answer: Z times SD=A, A+U=x

pg. 351 & 352

Question 9

What is the mean and SD for standard normal distribution?

Answer 9

Mean is always 0
SD is always 1

*only for stadard normal distribution

pg. 358

Question 10

What are the z-scores for standard normal distribution?

Answer 10

They are the values on the horizontal axis of the graph or along the bottom as it’s called the z-axis

pg. 358

Question 11

How do you use the calculator for standard normal distribution?

Answer 11

1. 2nd Distr
2. normalcdf
3. normalcdf(lower value, upper value, mean, SD)
   if no left endpoint use z=-1000 for lower value
   if no right endpoint use z=1000 for upper value

pg. 359

Question 12

How do you use the calculator to find the z-score when area is known?

Answer 12

1. 2nd Distr
2. invNorm
3. invNorm(area, mean, SD, location of area)

e.g. invNorm(.9,0,1,left)=1.281551567

pg. 367

Question 13

What is the relationship between normalcdf and invNorm?

Answer 13

They are opposites
normalcdf=area between
invNorm=z-score

pg. 369

Question 14

What is Z[subscript]a?

Answer 14

Z[sub]a is the z-score with an area of a to the right

a is called alpha so it reads z sub alpha

pg. 371