Deck 4: Percentiles,percentile Ranks,standard Scores,and the Normal Distribution

Question 1

The _____ of a set of standard scores is always equal to 0.

A)standard deviation
B)mean
C)sum
D)mean and sum

Answer 1

mean and sum

Question 2

The score value corresponding to a given percentile rank is referred to as a(n)_____.

A)optimal value
B)median value
C)standard score
D)percentile

Answer 2

percentile

Question 3

A survey finds that 50% of college students spend 10 hours or less on homework weekly.The percentile rank of _____ is _____.

A)50;10
B)10;50
C)50;50
D)cannot be determined

Answer 3

10;50

Question 4

In all normal distributions,the mean,the median,and the mode are all:

A)unequal to each other
B)standardized to 1.00
C)evenly distributed
D)equal to each other

Question 5

A _____ standard score indicates that the original score is _____ than the mean.

A)positive;greater
B)negative;less
C)a and b
D)neither a nor b

Question 6

The score value corresponding to a given percentile rank is referred to as a _____.

A)z-score
B)percentage
C)percentile
D)none of these

Question 7

All normal distributions are:

A)asymmetrical about the mean
B)characterized by a "bell shape"
C)positively skewed
D)a and b

Question 8

A percentile rank reflects a(n)_____ measure of relative standing.

A)nominal
B)ordinal
C)interval
D)ratio

Question 9

The _____ and the _____ of a set of standard scores is always equal to 1.00.

A)mean;variance
B)standard deviation;variance
C)variance;range
D)mean;standard deviation

Question 10

A standard score represents the number of _____ that a score falls above or below the mean.

A)units
B)percentile units
C)standard deviation units
D)standard score units

Question 11

All normal distributions are _____ in nature.

A)asymmetrical
B)theoretical
C)leptokurtic
D)all of these

Question 12

A standard score converts a score from its original,or raw form to a form that takes into consideration its standing relative to the _____ and _____ of the entire distribution of scores.

A)percentile;percentile rank
B)percentile;standard deviation
C)mean;percentile rank
D)mean;standard deviation

Question 13

The median corresponds to the _____ percentile.

A)50th
B)75th
C)average
D)standard

Question 14

In a frequency distribution,the term designating the score corresponding to the 50th percentile is known as the _____.

A)mean
B)median
C)mode
D)standard deviation

Question 15

One important use of standard scores is to compare scores on distributions that have different _____ and _____.

A)medians and IQRs
B)standard deviations and variances
C)means and standard deviations
D)none of these

Question 16

A survey finds that 80% of high school students scored at least 75 on a given intelligence test.The 80th _____ is _____.

A)percentile;75
B)value;75
C)score;75%
D)percentile;25

Question 17

The percentage of scores in the distribution that occur at or below a given value,X,is the _____ of that value.

A)standard score
B)percentile rank
C)percentile
D)rank

Question 18

The number of standard deviation units that a score falls above or below the mean is represented by the _____.

A)median frequency
B)percentile rank
C)relative frequency
D)standard score

Question 19

A standard score of _____ indicates that the original score is equal to the mean.

A)0
B)+1.00
C)-1.00
D)1.96

Question 20

The percentage of scores in a distribution that occur at or below a given value is the _____ of that value.

A)relative percentage
B)standard deviation
C)percentile rank
D)relative distribution

Question 21

It is always the case that _____ of the scores in a normal distribution occur above the mean and _____ of the scores in a normal distribution occur below the mean.

A).50;.50
B).75;.25
C)all;none
D).25;.75

Question 22

In a normal distribution,approximately _____ of all scores fall between the standard scores of -1.96 and +196.

A)95%
B)75%
C)66%
D)50%

Question 23

The proportion of scores occurring between standard scores of 0 and -1 is _____ the proportion of scores occurring between standard scores of 0 and +1.

A)equal to
B)less than
C)greater than
D)less than or equal to

Question 24

Standardization _____ the skewness and kurtosis of the scores.

A)affects
B)does not affect
C)minimizes
D)maximizes

Question 25

Another name for a standard score in a normal distribution is _____.

A)z score
B)percentile rank
C)z score in any distribution
D)cumulative relative frequency

Question 26

In a normal distribution,approximately _____ of all scores fall between standard scores of -3 and +3.

A)50%
B)68%
C)95%
D)99%

Question 27

In a normal distribution,approximately _____ of all scores fall between standard scores of -1 and +1.

A)50%
B)68%
C)95%
D)99%

Question 28

Standardization _____ the central tendency and variability of the scores.

A)affects
B)does not affect
C)minimizes
D)maximizes

Question 29

A set of scores that is positively skewed will _____ after they have been converted to standard scores.

A)be normalized
B)become negatively skewed
C)remain positively skewed
D)become platykurtic

Question 30

Given an approximately normal distribution of test scores with µ = 75,ó = 25,what test (raw)score would correspond to a z score of 1.5?

A)77.5
B)87.5
C)76.5
D)cannot be determined

Question 31

When a standard score is 0,the original (raw)score is equal to the _____ of the distribution.

A)mode
B)median
C)mean
D)standard deviation

Question 32

The sum of a set of standard scores for a distribution will _____ equal 0.

A)always
B)never
C)sometimes
D)cannot be determined

Question 33

John scores an 85 on his psychology exam.The other relevant characteristics of the distribution are as follows: = 75,s² = 4.What is John's standard score?

A)2.5
B)-2.5
C).625
D)-.625

Question 34

One property of normal distributions is that the proportion of scores that occur _____ is the same in all such distributions.

A)above or below a given standard score
B)between two specified standard scores
C)a and b
D)neither a nor b

Question 35

In a normal distribution,approximately 95% of all scores fall between standard scores of _____.

A)-1 and +1
B)0 and +2
C)-2 and +2
D)-3 and +3

Question 36

The process of standardizing scores _____ the basic shape of the distribution.

A)normalizes
B)changes
C)does not change
D)reveals

Question 37

The standard deviation of a set of standard scores in a distribution is _____.

A)100
B)50
C)1
D)0

Question 38

In a normal distribution,approximately _____ of all scores fall between the standard scores of -1 and +1.

A)50%
B)68%
C)33%
D)25%

Question 39

A _____ score in a _____ distribution is referred to as a z score.

A)raw;normal
B)standard;normal
C)raw;binomial
D)standard;binomial

Question 40

The mean of a set of standard scores for a given distribution is _____.

A)100
B)50
C)1
D)0

Question 41

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,
S² = 36.Approximately what percentage of scores falls at or between Nancy's and Ronald's scores?

A)75%
B)35%
C)11%
D)50%

Question 42

Given a normal distribution,what z score would correspond to the 50th percentile?

A)+1
B)-1
C)0
D)+.5

Question 43

Given a normal distribution of test scores with
= 80,s² = 49,what is the z score corresponding to a test score of 70?

A)-1.43
B)1.43
C)-2.1
D)22

Question 44

Given a normal distribution,what z score would correspond to the 95th percentile?

A)1.96
B)1
C)2
D)1.645

Question 45

Given a normal distribution of test scores with
= 80,s² = 49,what percentage of scores fall between the test scores of 70 and 95?

A)25%
B)64%
C)97%
D)91%

Question 46

For a T score with a mean of 50 and a standard deviation of 10,the T score equivalent to a standard score of 2.5 is _____.

A)2.5
B)52.5
C)3.5
D)75

Question 47

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,
S² = 36.What is Nancy's approximate percentile rank?

A)59
B)30
C)41
D)80

Question 48

A z score converts the raw score to a form that takes into consideration its standing relative to the _____ and _____ of the entire distribution of scores.

A)median;standard deviation
B)mean;standard deviation
C)mean;variance
D)median;interquartile range

Question 49

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,
S² = 36.What is Ronald's approximate percentile rank?

A).91
B)5
C)45
D)none of these

Question 50

Given a normal distribution of test scores with
= 80,s² = 49,what is the z score corresponding to a test score of 95?

A).31
B)-.31
C)2.14
D)-2.14

Question 51

John scored an 85 on his most recent psychology exam.Which of the following distributions would John least prefer (assuming he wishes to perform as well as possible,and higher test scores are more favorable)?

A)
= 80,s = 104
B)
= 80,s = 5
C)
= 70,s = 15
D)
= 70,s = 10

Question 52

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,s² = 36.What is Ronald's z score?

A)1.67
B)-1.67
C).28
D)-.28

Question 53

Suppose an approximately normal distribution of doctors' salaries finds µ = $150,000 and ó = $25,000.What salary level would define the 77th percentile?

A)$180,000
B)$168,000
C)$175,000
D)$158,250

Question 54

Percentile rank reflects a(n)_____ measure of relative standing.

A)nominal
B)interval
C)ratio
D)ordinal

Question 55

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,s² = 36.What is Nancy's z score?

A).14
B)-.14
C).83
D)-.83

Question 56

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,
S² = 36.What is Ronald's T score (for a mean of 50 and a standard deviation of 10)?

A)33.3
B)63.7
C)52.8
D)47.2

Question 57

The _____ of the standard score formula represents the number of units the score is above or below the mean.

A)numerator
B)denominator
C)obtained value
D)none of these

Question 58

An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,s² = 36.What is Nancy's T score (for a mean of 50 and a standard deviation of 10)?

A)51.4
B)5.14
C)5.83
D)58.3

Question 59

Approximately what proportion of a normal distribution lies between the z scores of +.66 and +1.55?

A)57%
B)63%
C)68%
D)32%

Question 60

A negative standard score indicates that the _____ was below the mean of the distribution.

A)raw score
B)sum of squares
C)standard deviation
D)none of these

Question 61

A psychologist is interested in how well people can remember words that they had previously seen.He gives them a list of 70 words,but does not tell them they will be tested later.One week later the students are given a list of 140 words,and told to choose the ones they had seen the previous week.Below is the grouped distribution of the number of words remembered by the subjects.
What is the percentile rank of a score of 47?

A)10
B)52.5
C)82.5
D)90

Question 62

Which of the following does a percentile rank and a standard score have in common?

A)both reflect the relative position of a score in a set of scores
B)both reflect only an ordinal measure of relative standing
C)both reflect the mean and standard deviation of the entire group of scores
D)all of these

Question 63

What is the standard score of a raw score of 30 from a set of 20 scores where the mean is 15 and the standard deviation is 5?

A)1
B)-1
C)3
D)-3

Question 64

A psychologist is interested in how well people can remember words that they had previously seen.He gives them a list of 70 words,but does not tell them they will be tested later.One week later the students are given a list of 140 words,and told to choose the ones they had seen the previous week.Below is the grouped distribution of the number of words remembered by the subjects.
What is the score at the 50^th percentile?

A)20
B)22
C)23
D)37

Question 65

Approximately what raw score in a normal distribution would correspond to a z score of 1.56 with
= 75 and s² = 4?

A)78
B)81
C)72
D)69

Question 66

A z score of _____ represents a raw score with a higher frequency than a standard score of _____.

A)-2.0;1.5
B)3.0;-.75
C)1.65;1.50
D)-.50;2.2

Question 67

A raw score of 96 on two separate examinations may have different _____ depending on the mean and standard deviations of each examination.

A)percentile ranks
B)standard scores
C)percentiles
D)all of these

Question 68

Percentile ranks must always be interpreted relative to the _____ upon which the scores are based.

A)group
B)scale
C)percentiles
D)all of these

Question 69

Based on the Method of Presentation section of Chapter 4,what would be the T score of a standard score of 2.5?

A)-4.75
B)2.5
C)75
D)135

Question 70

Based on the Applications to the Analysis of Social Problems section of Chapter 4,the formula referred to in question 1 above would most likely be used with

A)a normal distribution.
B)a positively skewed distribution.
C)a negatively skewed distribution.
D)both a and b
E)both b and c

Question 71

Given a normal distribution with a mean of 200 and a standard deviation of 30,what is the raw score corresponding to a z score of -2.0?

A)140
B)260
C)-6.73
D)-60

Question 72

The sum of a set of standard scores equals

A)0
B)1
C)the mean of the set of standard scores
D)both a and c
E)both b and c

Question 73

A psychologist is interested in how well people can remember words that they had previously seen.He gives them a list of 70 words,but does not tell them they will be tested later.One week later the students are given a list of 140 words,and told to choose the ones they had seen the previous week.Below is the grouped distribution of the number of words remembered by the subjects.
What is the percentile rank of a score of 12?

A)5
B)15
C)25
D)50

Question 74

Gary is told that his percentile rank on the law school admissions exam is 87.This indicates that 87% of students taking this exam scored _____ Gary.

A)higher than
B)higher than or equal to
C)lower than
D)lower than or equal to

Question 75

A psychologist is interested in how well people can remember words that they had previously seen.He gives them a list of 70 words,but does not tell them they will be tested later.One week later the students are given a list of 140 words,and told to choose the ones they had seen the previous week.Below is the grouped distribution of the number of words remembered by the subjects.
What is the score at the 90th percentile?

A)42.5
B)44.5
C)45
D)47

Question 76

Given a normal distribution with a mean of 50 and a standard deviation of 2,what is the z score of a raw score of 46?

A)-2
B)2
C)-4
D)4

Question 77

What proportion of scores in a normal distribution are between z = -1.75 and z = -2.75?

A).0371
B).0431
C).4599
D).4970

Question 78

Which of the following is a true property of a set of standard scores?

A)the mean is always one
B)the standard deviation is always one
C)they can only be positive numbers
D)they can only be negative numbers

Question 79

What proportion of scores in a normal distribution are between z = -2.62 and z = 1.07

A).1467
B).3577
C).4956
D).8533

Question 80

Based on the Applications to the Analysis of Social Problems section of Chapter 4,a variant of the standard scores formula may be calculated using the _____ and _____ instead of the mean and standard deviation,respectively.

A)median;range
B)median;median of absolute deviations
C)mode;interquartile range
D)mode;variance