Chapter 6: Part 1

Question 1

What do normal probability distributions allow us to make?

Answer 1

Inferences about all kinds of data

Question 2

What have mathematicians determined about normal distributions?

Answer 2

That they follow regular patterns, and by knowing the characteristics we can make inferences about data

Question 3

What can we use the standard normal table to determine?

Answer 3

The z-score that marks off a certain proportion of a population

Question 4

What can the normal distribution be used in place of?

Answer 4

The binomial distribution to determine probabilities when there are large numbers of observations

Question 5

What does a values position on the chart indicate?

Answer 5

Where a data point is relative to the others, both in terms of the value itself, but also in terms of frequency

Question 6

What will the distribution chart for any variable have?

Answer 6

Values and units of the variable on the x-axis and the frequency on the y-axis

Question 7

What does a normal distribution tell us for any particular value of the variable?

Answer 7

How common the value is, how far it is from the mean (above or below)

Question 8

What does the mean define?

Answer 8

Where the center of each distribution will be

Question 9

What does the standard deviation define?

Answer 9

The spread of the distribution

Question 10

What do narrower distributions have?

Answer 10

Smaller standard deviations

Question 11

What do wider distributions have?

Answer 11

Larger standard deviations with more variability among the values

Question 12

What is the formula for standard deviation?

Answer 12

o = square root o^2 (square root of the variance)

Question 13

What are the three properties of a normal curve?

Answer 13

Symmetric about the mean, all three measures of central tendency are the same, proportion of areas between the standard deviations are known

Question 14

What do the three properties of a normal curve create?

Answer 14

Family resemblance among the distributions of all variables that are normally distributed

Question 15

In a normal curve what are the sections of the normal curve defined by the standard deviation?

Answer 15

The same regardless of the value of the standard deviation

Question 16

What is a z-score?

Answer 16

Converts any individual raw value into a score that tells us how far that score is from the mean in terms of the standard deviation

Question 17

What is the standard normal distribution?

Answer 17

Makes it easier to apply the properties of the normal distribution to data collected on different scales

Question 18

What does combining z-scores with properties of the normal distribution allow us to know?

Answer 18

Where a score is relative to mean but also how much of the distribution falls above and below it

Question 19

What does the standard normal table tell us about z-scores?

Answer 19

What values are to the left of the z-score

Question 20

What do you do to find the value above a certain percentage from the z-score table?

Answer 20

You take the value that is below and subtract it from 1 to get the score of the value above

Question 21

How do you find the area between a z-score and the mean?

Answer 21

You can subtract the area given in the standard normal table for the z-score and subtract it from .5 to obtain the area of a z-score to the mean

Question 22

If finding the value from the score from the area of the mean which number do you put first?

Answer 22

Your value from the mean of .5000 (or the largest value that you have goes first)

Question 23

What parts do you know when you use the formula z= (X-u)/o ?

Answer 23

Raw score, the mean, and the standard deviation

Question 24

What is the simplified version of the z-score formula?

Answer 24

x= u + zo

Question 25

What are the characteristics of the normal curve?

Answer 25

Any area in a normal curve is distributed in the same way

Question 26

What does asymptomatic mean?

Answer 26

Curve never actually touches x-axis

Question 27

What is the proportion of scores?

Answer 27

Anything under normal curve is distributed in the same way

Question 28

What is the table body in a z-score table?

Answer 28

Represents the area of scores to the left of a respective z-score

Question 29

What is the first column in a z-table?

Answer 29

First digit of a z-score

Question 30

What is the first row of in the z-score table?

Answer 30

First two decimal places of a z-score

Question 31

What are the things you can do with a z-score?

Answer 31

Find area beyond a z-score, find the area between a z-score and the mean, find area between any two z-scores

Question 32

What happens if you can’t find the exact value?

Answer 32

Pick the larger score to get the smaller proportion