Deck 5: Normal Distributions

Question 1

Normal distributions ______.

A) are based on data collected from populations
B) are based on mathematical formulas
C) consist of a small number of scores
D) are a figment of our imagination

Answer 1

are based on mathematical formulas

Question 2

One of the characteristics of a normal distribution is that it ______.

A) is based on data collected by researchers
B) consists of a small number of scores
C) is based on mathematical formulas
D) is a figment of our imagination

Answer 2

is based on mathematical formulas

Question 3

Imagine the figure is designed to represent a normal distribution. What's one problem with it?

A) It should either be positively or negatively skewed.
B) It should be either a frequency polygon or a histogram.
C) The tails should not touch the X-axis.
D) It is too flat.

Answer 3

The tails should not touch the X-axis.

Question 4

Figure A is an example of a ______ distribution; Figure B is an example of a ______ distribution. Figure A Figure B

A) normal; theoretical
B) theoretical; skewed
C) frequency; normal
D) normal; frequency

Question 5

Imagine this figure is designed to represent a normal distribution. What is one problem with it?

A) It does not contain an infinite number of scores.
B) It is too peaked.
C) It should be skewed.
D) It does not consist of both positive and negative scores

Question 6

Moving from learning about frequency distributions to learning about normal distributions coincides with moving from learning about ______ to learning about ______.

A) how to collect data; how to analyze data
B) statistics used to describe data; statistics used to test hypotheses
C) parameters; statistics
D) independent variables; dependent variables

Question 7

The differences between frequency distributions and normal distributions reflect the difference between ______ and ______.

A) descriptive statistics; inferential statistics
B) analyzing data; examining data
C) testing hypotheses; proving hypotheses
D) the mean; the standard deviation

Question 8

______ are distributions based on a population of an infinite number of scores calculated from a mathematical formula.

A) Frequency distribution
B) Normal distribution
C) Sample distribution
D) z-score distribution

Question 9

The ______ of a normal distribution is equal to ______.

A) mean; σ
B) standard deviation; μ
C) standard deviation; 0
D) standard deviation; σ

Question 10

The ______ of the ______ is equal to ______.

A) mean; standard normal distribution; σ
B) standard deviation; normal distribution; μ
C) mean; standard normal distribution; 0
D) standard deviation; standard normal distribution; μ

Question 11

One difference between normal distributions and frequency distributions is that ______.

A) normal distributions are based on fewer scores than frequency distributions
B) frequency distributions represent samples; normal distributions represent populations
C) normal distributions are more skewed than frequency distributions
D) normal distributions are based on actual data; frequency distributions are hypothetical

Question 12

One difference between frequency distributions and normal distributions is that ______.

A) frequency distributions represent populations; normal distributions represent samples
B) frequency distributions are hypothetical; normal distributions are based on actual data
C) only normal distributions are based on mathematical formulas
D) frequency distributions consist of a greater number of scores than normal distributions

Question 13

One difference between normal distributions and frequency distributions is that ______.

A) normal distributions are based on fewer scores than frequency distributions
B) frequency distributions represent populations; normal distributions represent samples
C) normal distributions are more skewed than frequency distributions
D) normal distributions are hypothetical; frequency distributions are based on actual data

Question 14

This distribution is an example of a ______.

A) theoretical distribution
B) normal distribution
C) standard normal distribution
D) frequency distribution

Question 15

Moving from learning about frequency distributions to learning about normal distributions coincides with moving from learning about ______ to learning about ______.

A) the research process; how to analyze data
B) how to collect data; mathematical formulas
C) measures of central tendency; measures of variability
D) describing samples; testing hypotheses about populations

Question 16

Moving from learning about frequency distributions to learning about normal distributions coincides with moving from learning about ______ to learning about ______.

A) descriptive statistics; inferential statistics
B) central tendency; variability
C) statistical hypotheses; research hypotheses
D) statistical formulas; SPSS

Question 17

One difference between frequency distributions and normal distributions is that ______.

A) only frequency distributions are based on data collected by researchers
B) frequency distributions are based on formulas; normal distributions are based on data
C) frequency distributions are represented by parameters; normal distributions are represented by statistics
D) normal distributions are more likely to be skewed than frequency distributions

Question 18

The ______ of a normal distribution is equal to ______.

A) mean; μ
B) standard deviation; 0
C) mean; 1
D) mean;

Question 19

Normal distributions differ from frequency distributions in that ______.

A) normal distributions are based on data you have actually collected
B) frequency distributions are based on an infinite number of scores
C) normal distributions are based on mathematical formulas
D) frequency distributions are theoretical distributions

Question 20

Normal distributions ______.

A) are skewed (asymmetrical)
B) contain an infinite number of scores
C) are bimodal
D) always consist of both positive and negative scores

Question 21

Inferential statistics (statistics used to test research hypotheses) assume that ______.

A) variables are normally distributed in the population
B) variables are measured in z-scores
C) researchers collect data from people with normal personalities
D) researchers collect data from populations rather than from samples

Question 22

Normal distributions are an important concept to researchers because ______.

A) there is only one normal distribution
B) they do not actually exist
C) they are the basis of statistical techniques used by researchers
D) they help define 'normal' and 'abnormal' behavior

Question 23

One problem in using normal distributions is that ______.

A) how you interpret a score depends on how the variable is measured
B) there is only one normal distribution
C) they are skewed (asymmetric)
D) they do not actually exist

Question 24

The 'assumption of normality' refers to ______.

A) the shape of the distribution for a variable
B) people's behavior and personality
C) descriptive statistics
D) the nature of the relationship between samples and populations

Question 25

The belief that many variables are normally distributed in the population ______.

A) is only true when populations are very small
B) is referred to as the 'assumption of normality'
C) is the basis behind descriptive statistics
D) has been proven to be false

Question 26

Normal distributions are an important concept to researchers because they ______.

A) are based on data collected from samples
B) help researchers evaluate scores on variables
C) consist of a small number of scores
D) help define 'normal' and 'abnormal' behavior

Question 27

______ represents the ______ of a normal distribution.

A) σ; modality
B) ; modality
C) μ; variability
D) μ; modality

Question 28

In which of the following ways is the standard normal distribution similar to other normal distributions?

A) the unit of measurement
B) the total number of scores in the distribution
C) the mean of the distribution
D) none of these

Question 29

Except for ______, the standard normal distribution is similar to other normal distributions.

A) the symmetry of the distribution
B) the shape of the distribution
C) the total number of scores of the distribution
D) the unit of measurement of the distribution

Question 30

______ represents the ______ of a normal distribution.

A) σ; modality
B) μ ; symmetry
C) μ ; variability
D) σ; variability

Question 31

In which of the following ways is the standard normal distribution different from other normal distributions?

A) the mean of the distribution
B) the standard deviation of the distribution
C) the unit of measurement of the distribution
D) all of these

Question 32

The ______ of ______ is equal to ______.

A) mean; the standard normal distribution; 1
B) standard deviation; the standard normal distribution; μ
C) mean; a normal distribution; 1
D) standard deviation; a normal distribution; 1

Question 33

The ______ of a normal distribution is represented by ______.

A) symmetry; σ
B) modality; μ
C) modality; s
D) variability; μ

Question 34

Compared with other normal distributions, the standard normal distribution is similar in terms of ______.

A) the mean of the distribution
B) the standard deviation of the distribution
C) the unit of measurement of the distribution
D) the total number of scores in the distribution

Question 35

The standard normal distribution differs from other normal distributions in that only the standard normal distribution ______.

A) is measured in standard deviation units
B) consists of an infinite number of scores
C) is bell-shaped
D) is based on mathematical formulas

Question 36

In the standard normal distribution, the mean is equal to ______ and the standard deviation is equal to ______.

A) 1; 0
B) 0; 0
C) 0; 1
D) 1; 1

Question 37

Standard normal distribution scores are also known as ______.

A) frequencies
B) normal scores
C) z-scores
D) standard scores

Question 38

One problem in using normal distributions is that ______.

A) how you interpret a score depends on how a variable is measured
B) the sum of deviations from the mean is always equal to zero
C) they're based on a small number of scores
D) the use of the word 'normal' is seen as politically incorrect

Question 39

Normal distributions are an important concept to researchers because ______.

A) they are the basis of statistical techniques designed to test hypotheses
B) researchers typically collect data from entire populations
C) there is only one normal distribution
D) they are neither peaked nor flat

Question 40

In which of the following ways is the standard normal distribution (normal curve) similar to other normal distributions?

A) the standard deviation of the distribution
B) the symmetry of the distribution
C) the unit of measurement
D) none of these

Question 41

"Your score on this variable is about one-half of a standard deviation below the mean." Which of the following statements is MOST accurate?

A) Your z-score is 1.51.
B) Your z-score is -1.47.
C) Your z-score is -.53.
D) You cannot estimate your z-score with the information provided.

Question 42

The ______ of the standard normal distribution is equal to ______.

A) mean; σ
B) standard deviation; 0
C) standard deviation; μ
D) mean; 0

Question 43

"Your score on this variable is about two-thirds of a standard deviation below the mean." Which of the following statements is MOST accurate?

A) Your z-score is .67.
B) Your z-score is -.23.
C) Your z-score is -.65.
D) You cannot estimate your z-score with the information provided.

Question 44

"Your score is about half a standard deviation below the mean." Which of the following statements is MOST accurate?

A) Your z-score is .54.
B) Your z-score is -.19.
C) Your z-score is -.47.
D) Your z-score is -20%.

Question 45

About ______ of z-scores in the standard normal distribution are between the z-scores ±1.96.

A) one-third
B) half
C) two-thirds
D) 95%

Question 46

"Your score is about a standard deviation below the mean." Which of the following statements is MOST accurate?

A) Your z-score is -.93.
B) Your z-score is 1.04.
C) Your z-score is -.36.
D) Your z-score is 95%.

Question 47

"Your z-score is in the top 5% of the class." Which of the following statements is MOST accurate?

A) Your z-score is 5.
B) Your z-score is 2.
C) Your z-score is 0.
D) Your z-score is 1.

Question 48

"Your score is about three-fourths of a standard deviation above the mean." Which of the following statements is most accurate?

A) Your z-score is .71.
B) Your z-score is .34.
C) Your z-score is -.77.
D) You cannot estimate your z-score with the information provided.

Question 49

"Your score is about a standard deviation above the mean." Which of the following statements is most accurate?

A) Your z-score is -.97.
B) Your z-score is 34.13%.
C) Your z-score is .94.
D) You cannot estimate your z-score with the information provided.

Question 50

About ______ of z-scores in the standard normal distribution are within ±1 standard deviations of the mean.

A) one-third
B) half
C) two-thirds
D) 95%

Question 51

"Your score is almost two standard deviations above the mean." Which of the following statements is MOST accurate?

A) Your z-score is 1.80
B) Your z-score is 2.05.
C) Your z-score is -1.80.
D) Your z-score is 2.05

Question 52

About ____ of z-scores in the standard normal distribution are within ±2 standard deviations of the mean.

A) one-fourth
B) half
C) two-thirds
D) 95%

Question 53

"Your z-score on the exam is in the bottom 15% of the class." Which of the following statements is MOST accurate?

A) Your z-score is -1.10.
B) Your z-score is -15.
C) Your z-score is -15%.
D) Your z-score is -.25.

Question 54

Roughly all of the z-scores in the standard normal distribution are with in ______ standard deviations of the mean.

A) ±1
B) ±1.96
C) ±2
D) ±3

Question 55

About ______ of z-scores in the standard normal distribution are within ______ standard deviations of the mean.

A) 99%; ±1
B) half; ±2
C) two-thirds; ±3
D) 95%; ±2

Question 56

Roughly ______ of z-scores in the standard normal distribution are within ±3 standard deviations of the mean.

A) one-third
B) half
C) two-thirds
D) all

Question 57

About ______ of z-scores in the standard normal distribution are within ______ standard deviations of the mean.

A) 99%; ±3
B) half; ±1
C) two-thirds; ±2
D) 95%; ±1

Question 58

"Your score is around two standard deviations above the mean." Which of the following statements is MOST accurate?

A) Your z-score is 95%.
B) Your z-score is -2.06.
C) Your z-score is 1.94.
D) You cannot estimate your z-score with the information provided.

Question 59

The ______ of the standard normal distribution (normal curve) is equal to ______.

A) mean; σ
B) standard deviation; 1
C) mean;
D) standard deviation; σ

Question 60

About ______ of z-scores in the standard normal distribution are within ______ standard deviations of the mean.

A) half; ±3
B) two-thirds; ±1
C) 95%; ±1
D) 99%; ±2

Question 61

What percentage of z-scores in the standard normal distribution are greater than z = -1.03?

A) 15.15%
B) 34.85%
C) 65.15%
D) 84.85%

Question 62

What percentage of z-scores in the standard normal distribution are less than z = 2.36?

A) .91%
B) 49.09%
C) 50.91%
D) 99.09%

Question 63

What percentage of z-scores in the standard normal distribution are greater than z = -2.00?

A) 2.28%
B) 52.28%
C) 84.00%
D) 97.72%

Question 64

What percentage of z-scores in the standard normal distribution are between z = -.40 and z = .25?

A) 9.87%
B) 15.54%
C) 25.41%
D) 34.46%

Question 65

What z-score designates or marks the bottom 20% of the standard normal distribution?

A) -.20
B) ±.26
C) ±.52
D) -.84

Question 66

What percentage of z-scores in the standard normal distribution are greater than z = -1.40?

A) 8.08%
B) 41.92%
C) 58.08%
D) 91.92%

Question 67

What percentage of z-scores in the standard normal distribution are greater than z = .65?

A) .65%
B) 24.22%
C) 25.78%
D) 74.22%

Question 68

What percentage of z-scores in the standard normal distribution are between z = -.33 and z = .33?

A) 00.00%
B) 12.93%
C) 25.86%
D) 37.07%

Question 69

What percentage of z-scores in the standard normal distribution are between z = -.25 and z = .15?

A) 3.91%
B) 9.87%
C) 15.83%
D) 40.13%

Question 70

What percentage of z-scores in the standard normal distribution are less than z = -.35?

A) 13.68%
B) 36.32%
C) 63.68%
D) 86.32%

Question 71

What percentage of z-scores in the standard normal distribution are less than z = -.25?

A) 9.87%
B) -40.13%
C) 40.13%
D) 90.13%

Question 72

What percentage of z-scores in the standard normal distribution are less than z = -1.03?

A) -15.15%
B) 15.15%
C) 34.85%
D) 65.15%

Question 73

What percentage of z-scores in the standard normal distribution are less than z = -1.25?

A) 1.25%
B) 10.56%
C) 60.56%
D) 89.44%

Question 74

What percentage of z-scores in the standard normal distribution are greater than z = 1.11?

A) 1.11%
B) 13.35%
C) 36.65%
D) 86.65%

Question 75

What percentage of z-scores in the standard normal distribution are less than z = .20?

A) 42.07%
B) 57.93%
C) 84.00%
D) 92.07%

Question 76

What percentage of z-scores in the standard normal distribution are between z = -.20 and z = .40?

A) 7.53%
B) 23.07%
C) 42.07%
D) 76.93%

Question 77

What percentage of z-scores in the standard normal distribution are less than z = 1.45?

A) 7.35%
B) 42.65%
C) 92.65%
D) 42.51%

Question 78

The shaded area in this distribution most closely represents ______.

A) the % of z-scores between .00 and -1.72
B) the % of z-scores less than 1.49
C) the % of z-scores greater than -1.34
D) the % of z-scores less than -1.28

Question 79

The shaded area in this distribution is most likely to represent ______.

A) the % of z-scores between the mean and .75
B) the % of z-scores less than .75
C) the % of z-scores less than -.75
D) the % of z-scores greater than .75

Question 80

What percentage of z-scores in the standard normal distribution are less than z = .80?

A) 21.19%
B) 28.81%
C) 57.62%
D) 78.81%