Download Preview Sample 3

Test Bank to Accompany
Statistics for the Behavioral
and Social Sciences
Fifth Edition
by
Aron/Coups/Aron
Prentice Hall
Contents
Chapter 1
Displaying the Order in a Group of Numbers
Using Tables and Graphs
1
Chapter 2
The Mean, Variance, Standard Deviation, and Z Scores
20
Chapter 3
Correlation and Prediction
38
Chapter 4
Some Key Ingredients for Inferential Statistics:
The Normal Curve, Sample versus Population, and Probability
63
Chapter 5
Introduction to Hypothesis Testing
78
Chapter 6
Hypothesis Tests with Means of Samples
99
Chapter 7
Making Sense of Statistical Significance:
Effect Size and Statistical Power
118
Chapter 8
Introduction to the t Test: Single Sample and Dependent Means
136
Chapter 9
The t Test for Independent Means
165
Chapter 10
Introduction to the Analysis of Variance
191
Chapter 11
Chi-Square Tests and Strategies When Population Distributions
Are Not Normal
226
Applying Statistical Methods In Your Own Research Project
259
Chapter 12
Chapter 1 Displaying the Order in a Group of Numbers
Using Tables and Graphs
1) An education researcher collects data on how many students are on scholarship at various
local colleges. The researcher then makes a frequency table to summarize the data.
The researcher is using a(n):
A) measure of central tendency
B) descriptive statistical method
C) intuitive statistical method
D) inferential statistical method
Answer: B
2) A student theorizes that performance on a statistics exam will be related to the number of
hours she spent studying. This student will be required to use __________ to test
her theory.
A) common sense
B) reasoning by analogy
C) inferential statistics
D) intuition
Answer: C
3) The two main branches of statistical methods are:
A) theoretical and inferential
B) intuitive and observational
C) descriptive and intuitive
D) descriptive and inferential
Answer: D
4) The value of putting numbers into a frequency table is that:
A) it makes the pattern of numbers clear at a glance
B) it enables you to draw inferences from the table
C) frequency tables are required by many journals
D) all of the above
Answer: A
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5) A psychologist is interested in studying aggressive tendencies in people and develops a
measure of this personality characteristic. Aggression has become a(n) __________ in the
psychologist’s study.
A) abstract concept
B) variable
C) value
D) invariable construct
Answer: B
6) Several employees of a major corporation are rated for their degree of job satisfaction. If a
particular employee’s job satisfaction is rated 8 on a 20-point scale, 8 represents that
employee’s:
A) frequency
B) variable
C) score
D) percentile
Answer: C
7) An intelligence test includes 15 items. Thus, a person could get any number correct
between 0 and 15. Each of these numbers correct (0–15) that a person could possibly get
is called a:
A) value
B) variable
C) frequency
D) mean
Answer: A
8) The difference between scores of 3 and 4 is approximately the same as the difference
between scores of 15 and 16, the type of variable known as:
A) equal interval
B) differential
C) nondifferential
D) rank-order
Answer: A
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9) Numeric variables are also called:
A) nominal variables
B) categorical variables
C) quantitative variables
D) irrelevant variables
Answer: C
10) All of the following are examples of rank-order variables EXCEPT:
A) a student’s rank in his or her graduating class
B) a tennis player’s standing compared to other athletes in the region
C) a runner’s place finished in a race
D) a student’s level of stress just before an exam
Answer: D
11) Which of the following is NOT an example of a nominal variable?
A) Hair color
B) Religious affiliation
C) Social Security number
D) Score on an IQ test
Answer: D
12) Which of the following is an example of a nominal variable?
A) Grade point average (3.2, 2.7, etc.)
B) Number of friends a person has (0, 1, etc.)
C) Birth position in a family (first, second, etc.)
D) Nationality of the car a person owns (American, Japanese, etc.)
Answer: D
13) Which of the following is an example of an equal-interval variable?
A) Marital status of a person (single, divorced, etc.)
B) Number of friends a person has (2, 4, etc.)
C) Results of a horse race (arrived 1st, 2nd, etc.)
D) Numbers printed on the back of a basketball team’s jerseys (21, 43, etc.)
Answer: B
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14) A researcher wishing to summarize all the scores for a variable in a study creates a
frequency table, but finds that there are so many values that the table is too cumbersome to
be useful. The next step would be to make a:
A) histogram
B) frequency polygon
C) grouped frequency table
D) pie chart
Answer: C
15) A researcher measures the eye movements of 100 participants as they read ambiguous
words embedded within sentences. Because eye movements are measured in milliseconds,
and there are likely to be many different times measured, the researcher decides to use a
__________ to help make sense of these data.
A) frequency polygraph
B) scatterplot
C) grouped frequency table
D) horizontal bar chart
Answer: C
16) When making a frequency table for a numeric variable, the list down the left edge of the
page should include:
A) all possible values, starting from the highest and ending with the lowest
B) only even-numbered values
C) only odd-numbered values
D) the cumulative frequencies and percentages for female participants
Answer: A
17) When making a frequency table for a nominal variable, the values listed on the left-hand
side of the frequency table should be:
A) the percent correct
B) the number of social interactions per week
C) the categories of the variable
D) the appropriate interval groupings
Answer: C
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18) A frequency table lists:
A) the times per second that variations occur in various wave bands
B) the number of scores at each value
C) the intensity of a variable over all the participants studied
D) the average and median values of each variable
Answer: B
19) A frequency table includes columns for all of the following EXCEPT:
A) the number of ratings for each value on a scale
B) the frequency of scores at each value
C) the percentage of scores for each value
D) the standard deviation of the measurement scale
Answer: D
20) The word “frequency” in a frequency table refers to:
A) cycles per second
B) the number of scores at each value of a variable
C) the times per unit change of each score
D) the cumulative percentage for any given value
Answer: B
21) Consider the scores 1, 3, 3, 5, 6, 6, 6, 7, 7, 8. Which of the following would be the correct top
line of a frequency table?
A) 3, 2, 20%
B) 10, 10, 100%
C) 0, 2, 25%
D) 8, 1, 10%
Answer: D
22) Consider the scores 2, 6, 7, 1, 7, 8, 5, 4. Which of the following would be the correct second
line of the frequency table?
A) 2, 7, 20%
B) 7, 2, 25%
C) 6, 1, 6%
D) 1, 1, 12%
Answer: B
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23) A histogram looks most like:
A) the skyline of a city
B) a large wave
C) a silhouette of mountains
D) a pattern of iron filings
Answer: A
24) A histogram is most closely related to which of the following?
A) Pie chart
B) Line plot
C) Contour plot
D) Bar chart
Answer: D
25) In a histogram, the vertical (up and down) dimension displays:
A) possible values the variable can have
B) intensity of the variable
C) mean score
D) frequency
Answer: D
26) In a histogram, the horizontal dimension displays a:
A) range of possible values the variable can have
B) percentile score for each individual
C) mean score
D) frequency
Answer: A
27) When working with a nominal variable, the histogram is called a(n):
A) bar graph
B) frequency polygon
C) area plot
D) bubble plot
Answer: A
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28) When making a histogram, it is easiest if you begin with a:
A) list of all the scores in order
B) frequency table
C) list all of the percentages in order
D) normal curve table
Answer: B
29) An important difference between a histogram and a frequency polygon is that the
frequency polygon:
A) is used for grouped values
B) begins and ends with a frequency of 10 (i.e., at the y-axis)
C) covers the full range of values (i.e., 0–100)
D) begins and ends with a frequency of zero (i.e., at the horizontal axis)
Answer: D
30) A frequency polygon looks most like:
A) the skyline of a city
B) a large wave
C) a silhouette of mountains
D) a series of intersecting shapes
Answer: C
31) Place the five steps for making a frequency polygon into the correct order:
1. Along the left side of the page (y-axis), make a scale of frequencies that ranges from 0 at
the bottom to the highest frequency for any value.
2. Connect the points with lines.
3. Make a frequency table.
4. Mark a point above each value with a height for the frequency of that value.
5. Put the values along the bottom of the page (x-axis).
A) 3, 5, 1, 4, 2
B) 2, 3, 1, 4, 5
C) 5, 3, 1, 2, 3
D) 3, 5, 1, 2, 4
Answer: A
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32) Social scientists use frequency tables, histograms, or frequency polygons to show:
A) the relation between two variables
B) the reasoning behind experiments
C) specific hypotheses and test their validity
D) how the data they collect are distributed
Answer: D
33) Why might a frequency polygon include an extra value at the start and end along
the bottom?
A) To illustrate the bimodal distribution of the data
B) To highlight the value with the largest frequency
C) To make a closed figure (i.e., polygon)
D) To construct a rectangular distribution
Answer: C
34) The distribution of scores in a research study in the behavioral and social sciences
is usually:
A) unimodal
B) bimodal
C) multimodal
D) rectangular
Answer: A
35) A researcher rates participants’ empathic responses to the distress of strangers on a scale of
1 to 10. Most participants were rated either 3 or 7. How would this distribution
be described?
A) Bimodal
B) Unimodal
C) Rectangular
D) Normal
Answer: A
36) If all the values in a distribution have about the same frequency, it is called a(n):
A) multimodal distribution
B) rectangular distribution
C) bimodal distribution
D) equalized distribution
Answer: B
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37) On the first exam in an introductory statistics class most students did very well and only a
few did poorly. How would you describe the distribution of test scores?
A) Symmetrical
B) Skewed to the left
C) Having a floor effect
D) Skewed to the right
Answer: B
38) On an exam in a cognitive psychology class, most students attained a perfect score. This is
an example of:
A) a symmetrical distribution
B) a bimodal distribution
C) a ceiling effect
D) a floor effect
Answer: C
39) When a distribution is skewed to the right, it means that:
A) there are more scores piled up at the high end of the range
B) the scores are evenly distributed
C) there are more scores piled up at the low end of the range
D) there is a ceiling effect
Answer: C
40) When a distribution is skewed to the left, it is likely that:
A) there is a floor effect
B) there are more scores piled up at the low end of the range
C) the distribution is approximately normal and symmetrical
D) there is a ceiling effect
Answer: D
41) In some cases, researchers describe a distribution in terms of whether its tails have many or
few scores in them. This aspect of the shape of a distribution is known as:
A) symmetry
B) kurtosis
C) z-transformation
D) queue
Answer: B
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42) When a distribution is heavy-tailed it means that:
A) it has a flat appearance with many scores at the extremes (tails)
B) it is skewed to the right
C) it is skewed to the left
D) it has a pinched appearance with few scores at the extremes (tails)
Answer: A
43) A frequency table is most likely to be included in a research article when:
A) nominal variables are involved
B) there are a very small number of scores
C) a correlation is being reported
D) there are only two values for the variable
Answer: A
44) If you suffer from test anxiety, some useful advice is to:
A) overprepare for tests (at least at first)
B) learn methods to breathe properly and deeply
C) create a practice test situation that is similar to the real test
D) all of the above
Answer: D
45) Which of the following is supported by research cited in your text?
A) Women generally do worse in statistics classes because they have lower expectations
for themselves.
B) Women tend to do worse in statistics because others have lower expectations
of them.
C) Women tend to do worse in statistics because instructors generally call on them
less often.
D) Women generally do as well as men in statistics classes.
Answer: D
46) Research by Wolf, Van Doorn, and Weissing (2008) indicates that high sensitivity,
reactivity, or responsiveness:
A) are innate traits found in about 15–20% of humans
B) are related to a tendency to reflect before acting, rather than rushing into things
C) are related to a tendency to have strong emotional reactions to events
D) all of the above
Answer: D
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47) According to your text, Hyde and Mertz (2009) found that the more gender equality that
exits in a society, the more likely it is that women are equal to men in terms of math
performance, and the greater likelihood that women have “profound mathematical talent.”
(True or False).
Answer: TRUE
48) Match the term on the left with its correct definition on the right:
A) ceiling effect
1) distribution with many scores at each of the two
extremes (tails)
B) heavy-tailed distribution
2) specific, mathematically defined, bell-shaped
frequency distribution commonly observed in nature
C) light-tailed distribution
3) situation in which many scores pile up at the high
end of a distribution (creation skewness to the left)
D) normal curve
4) distribution with few scores at each of the two
extremes (tails)
Answer: A-3; B-1; C-4; D-2
Questions 49 and 50 refer to the table below.
Incidence of Memory, Language, and Motors Deficits in
Alzheimer’s Disease Patients (N = 200)
Cognitive Symptom
Memory Problems
Language Problems
Motor Problems
N
%
180
64
40
90%
32%
20%
49) According to the table, what is the most common types of cognitive problem faced by
Alzheimer’s disease patients?
A) Motor problems
B) Language problems
C) Memory problems
D) Attentional problems
Answer: C
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50) According to the table, what is the total number of patients in this sample who suffer from
motor problems?
A) 20/200
B) 40
C) 40/N
D) 64
Answer: B
51) Social scientists use __________ to summarize and make understandable a group of
numbers collected in a research study.
Answer: descriptive statistics
52) Researchers use __________ to draw statistical conclusions that go beyond the numbers
actually collected in the research.
Answer: inferential statistics
53) A listing that shows how many times each value of a variable occurs among a particular
group of scores is called a(n) __________.
Answer: frequency table
54) A test of social skills is administered to all professors at a local college. The __________ of a
particular professor is 81.
Answer: score
55) In a study of hospitalized psychiatric patients, the __________ of interest is how well the
patients can take care of their rooms, as rated by the nurses on a scale of 0 to 7.
Answer: variable
56) On a measure of social skills, the difference between scores of 6 and 7 has the same
meaning as a difference between scores of 25 and 26. This measure is considered a(n)
__________ variable.
Answer: equal-interval
57) Another name for an ordinal variable is a(n) __________ variable.
Answer: rank-order
58) Equal-interval and rank-order variables are both __________ variables.
Answer: numeric, quantitative
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59) The type of transportation a person uses to get to work (e.g., car, bus) is an example of a(n)
__________ variable.
Answer: nominal, categorical
60) When making a frequency table, the values are listed in the first column and the
__________ for each value is listed in the second column.
Answer: frequency
61) The third column of a frequency table usually contains __________.
Answer: percentages, %
62) A business researcher set up a __________ that lists the number of employees for each level
of earnings, from the level of $80,000–99,999, going down to the level of $20,000–29,999.
Answer: grouped frequency table
63) A way to simplify a frequency table when there are a large number of possible values is to
group the scores into __________.
Answer: intervals
64) A frequency table, histogram, or frequency polygon describes a(n) __________.
Answer: frequency distribution, distribution of scores
65) A drawback associated with the use of grouped frequency tables is that you lose
information about the breakdown of frequencies within each interval. (True or False)
Answer: TRUE
66) Frequency tables can be used for numerical but not nominal variables. (True or False)
Answer: FALSE
67) The histogram of a(n) __________ distribution has one of the bars higher than all the others.
Answer: unimodal
68) In a study of exercise behavior, a researcher found that the shape of the distribution of the
number of hours exercised was __________ because one large group of people did not
exercise at all while another large group all exercised approximately hours per week.
Answer: bimodal
69) The number of times the various numbers on a roulette wheel come up, in the long run,
form a(n) __________ frequency distribution.
Answer: rectangular, symmetrical
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70) A distribution is called __________ when the pattern of frequencies on the left and right
side are mirror images of each other.
Answer: symmetrical
71) A distribution in which the scores pile up on one end and are spread out on the other end
is an example of a(n) __________ distribution.
Answer: skewed
72) On a particular test of reading ability (in which high scores mean high reading ability), the
distribution of adults is skewed to the __________ because most adults have fairly good
reading ability, but a small number of people are nearly illiterate.
Answer: left
73) The distribution of data collected in behavioral and social science research studies often
approximates a(n) __________.
Answer: normal curve
74) A rectangular distribution, in addition to being symmetrical, would be an example of a(n):
__________.
Answer: heavy-tailed distribution
75) Explain the difference between descriptive and inferential statistical methods. Provide an
example of how each of these methods might be used in a study examining the effects of a
behavioral intervention for children with autism.
76) Explain why a grouped frequency table can sometimes be more useful than an ordinary
frequency table for categorizing and displaying a group of numbers.
77) You are asked to develop a new measure of leadership ability to be used in a study of
adolescent behavior (with male and female students in Grades 6–8). (a) What is the
variable of interest in this study? (b) Is your variable equal-interval, rank-ordered, or
nominal? (c) Describe the nature of your measure and its range of values. (d) Do you
anticipate a normal distribution of scores on your variable? If not, what do you expect to
find with regard to the shape of your distribution?
78) Explain what it means to have a ceiling effect in a distribution of scores. Provide an
example.
79) Sketch the following: (a) a normal distribution, (b) a bimodal distribution, (c) a positively
skewed distribution, and (d) a heavy-tailed distribution.
80) Make up an example of a distribution that would be much more peaked than usual.
81) Make up a study that would produce a distribution that is bimodal.
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82) Make up a study that would produce a distribution that is rectangular.
83) A developmental psychologist studied how long it took toddlers to pick up a particular
attractive new toy. Fifty toddlers were studied, all of whom eventually picked up the toy.
In the research article, the psychologist provided the following table for the approximate
number of minutes it took to lift the toy.
Minutes
10
9
8
7
6
5
4
3
2
1
f
7
0
3
5
7
8
9
7
2
1
%
14
0
6
10
14
16
18
14
4
2
(a) Using this table as an example, explain the idea of a frequency table to a person who
has never had a course in statistics.
(b) Explain the general meaning of the pattern of results (sketch a frequency graph
if necessary).
84) An anthropologist examined the average number of children in a particular group of 84
hunter-gatherer societies. The anthropologist reported that the distribution was bimodal.
Explain what this means to a person who has never had a course in statistics.
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85) A sociologist surveyed 16 single senior citizens living in private apartments. Each
participant completed a questionnaire on the number of telephone conversations he or she
had had in the last day. Their answers were as follows: 5, 0, 2, 1, 1, 9, 0, 1, 0, 3, 1, 1, 4, 3, 4, 7.
Construct a frequency table.
Make a histogram based on the frequency table.
Describe in words the shape of the histogram.
Answer: X
9
8
7
6
5
4
2
1
0
f
1
0
1
0
1
2
1
5
3
%
6.3
0.0
6.3
0.0
6.3
12.5
6.3
31.3
18.8
86) A researcher recorded the numbers of rule infractions for 12 prison inmates over a 6-month
period and found them to be 1, 3, 0, 1, 0, 6, 8, 2, 0, 1, 0, 2.
Construct a frequency table.
Make a histogram based on the frequency table.
Describe in words the shape of the histogram.
Answer: X
8
7
6
5
4
3
2
1
0
f
1
0
1
0
0
1
2
3
4
%
8.3
0.0
8.3
0.0
0.0
8.3
16.7
25.0
33.3
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87) A study recorded the number of units produced per hour by 15 factory workers. The
results were as follows: 8, 10, 4, 9, 9, 10, 1, 9, 8, 5, 9, 9, 8, 7, 8.
Construct a frequency table.
Make a frequency polygon based on the frequency table.
Describe in words the shape of the frequency polygon.
Answer: X
10
9
8
7
6
5
4
3
2
1
f
2
5
4
1
0
1
1
0
0
1
%
13.3
33.3
26.7
6.7
0.0
6.7
6.7
0.0
0.0
6.7
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88) A political scientist surveyed 20 active members of a small political action group about
how many hours they spent on the group’s activities each week. The results were as
follows: 24, 41, 1, 41, 14, 2, 40, 58, 2, 1, 41, 2, 41, 30, 0, 41, 3, 3, 41, 49.
Make a grouped frequency table using intervals from 0–9, 10–19, etc.
Make a histogram based on the grouped frequency table.
Describe in words the shape of the histogram.
Answer:
(example): Interval
50–59
40–49
30–39
20–29
10–19
0–9
f
1
8
1
1
1
8
%
5.0
40.0
5.0
5.0
5.0
40.0
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89) On the first day of class, a statistics professor asks her students to report their eye color.
These data are distributed as follows: green = 25 students, brown = 55 students, blue = 30
students, other = 6 students.
What is the variable of interest in this study?
What type of variable is this?
Construct a frequency table for these data.
Sketch a bar graph for these data.
Answer: eye color
nominal/categorical
Color
Green
Brown
Blue
Other
f
25
55
30
6
%
21.5%
47.5%
26%
5%
Eye Color of Students
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19
Chapter 2 The Mean, Variance, Standard Deviation,
and Z Scores
1) The representative value of a group of scores refers to the middle of the group of scores.
All of the following are types of representative values EXCEPT:
A) mean
B) metric
C) mode
D) median
Answer: B
2) A researcher observes the level of aggression of six 5-year-old boys over the course of a
school day. The number of incidents for the group of boys was 2, 4, 6, 12, 8, 10. What is the
mean number of aggressive acts for this group of children?
A) 4
B) 5
C) 7
D) 9
Answer: C
3) Five people’s scores on a survey of product recognition are 17, 12, 20, 13, 8. What is their
mean score?
A) 12
B) 13
C) 14
D) 10
Answer: C
4) The ordinary average of a group of numbers is called the __________.
A) median
B) mean
C) standard deviation
D) mode
Answer: B
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5) The rule for calculating the mean is to add up all the scores in a sample and divide by the
__________.
A) median
B) number of scores minus 1
C) number of scores
D) most frequent score
Answer: C
6) Based on the scores 1, 9, 3, 6, 1, 2, 6, 2, 2, 8, a score of 4 is the __________.
A) mode
B) median
C) mean
D) standard deviation
Answer: C
7) In statistical formulas, what does N stand for?
A) The number of different values possible on the variable
B) The number of scores in a distribution
C) The normal curve
D) The normalized Z score in a distribution of scores
Answer: B
8) A research team studied the rate at which infants in the three different countries vocalized
distress. Below are the scores from each country. Which group of infants showed the
highest mean rate of distress vocalization over the 45-minute observation period?
Country A: 9, 9, 10, 13, 8, 8, 11, 11, 10, 7, 13, 6, 18, 9, 9, 12, 13, 10, 5, 14
Country B: 15, 15, 16, 19, 14, 14, 17, 17, 16, 13, 19, 12, 18, 10, 10, 15, 15, 2, 2, 5
Country C: 4, 6, 20, 17, 15, 30, 18, 18, 25, 2, 29, 17, 16, 35, 19, 1, 30, 25, 16, 15
A) Country A
B) Country B
C) Country C
D) Countries B and C were equal
Answer: C
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9) The most common single number in a group of scores is the:
A) mode
B) mean
C) median
D) average
Answer: A
10) What is the mode of the following scores: 3, 4, 6, 7, 10, 10, 30, 10, 30, 4, 3, 8 ?
A) 3
B) 4
C) 8.5
D) 10
Answer: D
11) Based on the following scores 1, 2, 3, 4, 5, 6, 8, 8, 8, 9, 10, a score of 8 is the:
A) mean
B) median
C) mode
D) standard deviation
Answer: C
12) What is the median of the following group of scores: 1, 2, 2, 3, 4, 4, 4, 6, 8, 10?
A) 3
B) 5.5
C) 4
D) 3.5
Answer: C
13) The middle value in a set of scores lined up from lowest to highest is the:
A) mean
B) mode
C) average
D) median
Answer: D
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14) What is the median of the following scores: 4, 4, 6, 7, 8, 8, 9, 10, 11, 2, 1, 4?
A) 4
B) 5.5
C) 6.5
D) 8.5
Answer: C
15) A Canadian political scientist discovers that the number of members of their provincial
parliament that a group of voters can name is as follows: 3, 3, 3, 4, 4, 5, 6, 7, 8, 9, 10, 35.
Upon examination of these scores, the researcher would probably decide to use which
measure of the typical value?
A) Mean
B) Median
C) Mode
D) Standard deviation
Answer: B
16) Which statement is true for the scores 1, 2, 3, 4, 5, 5, 7, 8, 9, 10, 12, 12, 13?
A) The mode is greater than the median
B) The median is greater than the mean
C) The median is greater than the mode
D) The mode is greater than the mean
Answer: C
17) When a distribution is skewed to the right:
A) the median is greater than the mean
B) the mean and the median are the same
C) the mean is greater than the median
D) the mean and the median are equal
Answer: C
18) The median is greater than the mean in a distribution that is:
A) symmetrical
B) skewed to the right
C) normal
D) skewed to the left
Answer: D
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19) The capital Greek letter “sigma” is the symbol for:
A) “average of”
B) “sum of”
C) “variance of”
D) “median of”
Answer: B
20) In a perfectly symmetrical unimodal distribution:
A) there are two values with the highest frequency of scores
B) the mode is slightly less than the mean
C) the mean is larger than the median
D) the mode is the same as the mean
Answer: D
21) The mode can be a poor representative value because:
A) it can be difficult to calculate without a statistical software package
B) it does not reflect many aspects of the distribution
C) it is generally larger than the mean
D) all of the above
Answer: B
22) The ________ is the usual way of describing the representative value for a nominal variable
such as religious affiliation.
A) mean
B) outlier
C) median
D) mode
Answer: D
23) In a distribution with an even number of scores, the median will be the:
A) most common value
B) average of the two middle scores
C) the median divided by the mean
D) the sum of score divided by N – 1
Answer: B
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24) Unless there are __________ , behavioral and social scientists generally use the mean as the
measure of the representative value of a group of scores.
A) outliers
B) histograms
C) Z scores
D) two modes
Answer: A
25) While the mean provides a representative value of a group of scores, it does not tell about
the __________.
A) variability of the scores
B) average of the scores
C) spread of the scores around the mean
D) both A and C
Answer: D
26) Place the five steps for computing variance into the correct order:
1. Divide the sum of squared deviations by the number of scores.
2. Subtract the mean from each score.
3. Add up the squared deviation scores.
4. Compute the mean of the sample.
5. Square each of the deviation scores.
A) 2, 3, 1, 4, 5
B) 5, 1, 2, 4, 3
C) 4, 5, 2, 1, 3
D) 4, 2, 5, 3, 1
Answer: D
27) In order to compute the range of a group of scores, one must:
A) subtract the lowest score from the highest score
B) multiply the lowest score by the average
C) multiply the highest score by the average
D) subtract the lowest score from the highest and divide by N
Answer: A
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28) The variance of a group of scores is the same as the:
A) average of the squared deviations from the mean
B) sum of the squared deviations about the mean
C) average of the absolute deviations from the mean
D) sum of the absolute deviations from the median
Answer: A
29) In a class of students in which everyone is exactly 24 years old, the variance would be:
A) approximately 1
B) exactly 0
C) between 0 and 1
D) impossible to determine without more information
Answer: B
30) The variance of a group of scores is 9. What is the standard deviation?
A) 1
B) 3
C) 4.5
D) 81
Answer: B
31) The most widely used way of describing the spread of a group of scores is the:
A) range
B) variance
C) square root transformation
D) standard deviation
Answer: D
32) Roughly speaking, the standard deviation is the average amount that scores differ from
the:
A) histogram
B) median
C) mean
D) range
Answer: C
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33) The standard deviation is defined as the:
A) positive square root of the variance
B) positive square root of the range
C) negative square root of the variance
D) positive square root of the mean or median
Answer: A
34) Measures of variability, such as the variance and standard deviation, are heavily
influenced by the presence of one or more:
A) average scores
B) computational formulas
C) variables
D) extreme scores or outliers
Answer: D
35) The standard deviation of a group of scores is 4. What is the variance?
A) 2
B) 4
C) 8
D) 16
Answer: D
36) A researcher surveys job satisfaction among laborers and white-collar workers. (Job
satisfaction is rated on a scale from 1 = low satisfaction to 10 = high satisfaction.) Results
show that laborers have a mean job satisfaction score of 3 and a variance of 1; white-collar
workers have a mean job satisfaction rating of 7 and a variance of 10. Which statement best
describes what these numbers mean?
A) White-collar workers are less satisfied than laborers.
B) White-collar workers and laborers are about equally satisfied.
C) Laborers generally are less satisfied than white-collar workers, but laborers are just as
likely to be highly satisfied as white-collar workers are to be highly dissatisfied.
D) Laborers are less satisfied than white-collar workers and most laborers are about
equally dissatisfied while there is more variation in the satisfaction of white-collar
workers.
Answer: D
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37) What is the variance of these three scores: 1, 4, 7?
A) 3
B) 4
C) 6
D) 9
Answer: C
38) What is the variance of these four scores: 0, 1, 1, 2?
A) .25
B) .5
C) .86
D) 1
Answer: B
39) What is the standard deviation of these four scores: 2, 4, 3, 7?
A) 1.87
B) 2.35
C) 3.50
D) 4.05
Answer: A
40) In a distribution of Z scores, the mean is always:
A) 10
B) 1
C) 0
D) 50
Answer: C
41) A __________ describes a particular score in terms of where it fits into the overall group of
scores.
A) standard deviation
B) computational formula
C) Z score
D) Q score
Answer: C
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42) All of the following are true statements about a Z score EXCEPT:
A) it is the number of standard deviations the actual score is above or below the mean
B) it is negative if the actual score falls below the mean
C) it is negative if the actual score falls above the mean
D) it is zero if the actual score falls at the mean
Answer: C
43) Donald’s score on the statistics test was +1.25. This means that he scored:
A) slightly below the average
B) just at the average
C) a little less than one standard deviation below the mean
D) more than one standard deviation above the mean
Answer: D
44) As compared to a Z score, a raw score is:
A) a transformed score
B) an ordinary score
C) a scaled score
D) a standardized score
Answer: B
45) Which of the following is NOT an advantage of Z scores?
A) You can compare scores from scales with different amounts of variation.
B) You can easily tell if a score is above or below the mean.
C) You can easily tell how far above or below the mean a score is.
D) You can easily tell the shape of the scores’ distribution.
Answer: D
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46) For the questions below: A statistics student (Lee) wants to compare his final exam score to
his friend Zoey’s final exam score from last year. However, the two exams were scored on
different scales. Lee asks Zoey for the mean and standard deviation of her class on the
exam as well as her final exam score. Compute the Z scores for Lee and Zoey.
Lee: Final exam score = 85; Class: M = 70; SD = 10
Zoey: Final exam score = 45; Class: M = 35; SD = 5
A) Lee, Z = 1.50; Zoey, Z = 2.00
B) Lee, Z = −1.07; Zoey, Z = −1.14
C) Lee, Z = 1.07; Zoey, Z = −1.14
D) Lee, Z = 1.07; Zoey, Z = 1.50
Answer: A
47) In relation to the other people in their classes, who had the better exam score?
A) Lee
B) Zoey
C) They were equal
D) It is not possible to say without more information
Answer: B
48) A Z score of 2.0 came from a distribution with a mean of 80 and a standard deviation of 10.
What is the raw score?
A) 82
B) 90
C) 100
D) 170
Answer: C
49) A person’s raw score is 7, the mean is 13, and the standard deviation is 3. What is the
person’s Z score?
A) −2
B) −1
C) 1
D) 2
Answer: A
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50) A raw score is equal to the:
A) Z score multiplied by the standard deviation, plus the mean
B) Z score multiplied by the variance, plus the mean
C) standard deviation multiplied by the mean, plus the variance
D) raw score minus the mean, divided by the variance
Answer: A
51) For a particular group of scores, M = 20 and SD = 5. What is the Z score for a raw score of
10?
A) 2
B) 0
C) −2
D) −1
Answer: C
52) For a particular group of scores, M = 15 and SD = 3. Provide the raw score for a Z score of 7:
A) 15
B) 24
C) 36
D) 48
Answer: C
53) Who was the behavioral psychologist opposed to the use of statistics in psychology?
A) Cohen
B) McCracken
C) Cronbach
D) Skinner
Answer: D
54) A researcher studying the sociological implications of cultural diversity conducts lengthy
interviews with members of various cultural communities. What kind of method is this
sociologist probably using?
A) Behavioral techniques
B) Quantitative techniques
C) Qualitative techniques
D) Positivistic techniques
Answer: C
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55) Although __________ and __________ are often provided in research articles (in the text or
tables), _________ are rarely reported.
A) variance, range, Z scores
B) Z scores, T scores, means
C) means, standard deviations, Z scores
D) outliers, Z scores, means
Answer: C
56) Match the term on the left with its correct definition on the right
A) definitional formula
1) ordinary score (or any other number in a distribution
before it has been made into a Z score)
B) raw score
2) approximately the average amount that scores in a
distribution vary from the mean
C) Z score
3) equation for a statistical procedure directly showing
the meaning of the procedure
D) standard deviation
4) number of standard deviations a score is above or
below the mean of its distribution
Answer: A-3; B-1; C-4; D-2
57) Whose name is associated with behaviorism and opposition to the field of statistics on the
basis that important information may be lost by averaging the results of a number of cases?
A) James
B) Freud
C) Wolpe
D) Skinner
Answer: D
58) Qualitative research techniques are likely to involve each of the following EXCEPT:
A) lengthy interviews
B) focus groups
C) quantitative methods (e.g., statistics)
D) observations of individuals (e.g., in natural settings)
Answer: C
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32
59) A research article states that “At the time of the study, the mean age of first-year college
students at Wayne University was 17.6 (3.57). The number in parentheses likely represents:
A) the Z score
B) the standard deviation
C) the mode
D) an outlier
Answer: B
60) The ordinary arithmetic average is called the __________.
Answer: mean
61) The mean of the scores 2, 2, 2, 6 is __________.
Answer: 3
62) A group of scores is 6, 7, 7, 8, 10, 11. What is N?
Answer: 6
63) The __________ is the value with the most scores.
Answer: mode
64) A group of scores is 2, 2, 4, 8, 9, 2, 10, 15, 30, 30. What is the mode?
Answer: 2
65) A group of scores is 6, 18, 4, 21, 22. __________ is the median.
Answer: 18
66) In statistics, the best measure of the representative value of a group of scores is usually the
mode. (True or False)
Answer: FALSE
67) In a perfectly symmetrical unimodal distribution, the mode is the same as the mean. (True
or False)
Answer: TRUE
68) A group of scores is 2, 2, 4, 8, 9, 25. What is the median?
Answer: 6
69) A group of scores is 2, 81, 82, 82, 84, 86, 90. The number __________ is an outlier.
Answer: 2
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70) The variance of a group of scores is the average of the __________.
Answer: squared deviations from the mean, squared deviations
71) The variance of the scores 1, 7, 13 is __________.
Answer: 24
72) A deviation score is the difference between the score and the __________.
Answer: mean
73) The __________ is approximately the average that a score differs from the mean.
Answer: standard deviation
74) The standard deviation is the __________ of the variance.
Answer: square root, positive square root
75) A(n) __________ is the number of standard deviations a score is above or below the mean.
Answer: Z score
76) A Z score is −3 and the sample’s M = 30 and SD = 6. The raw score is __________.
Answer: 12
77) A raw score is 28, M = 20, and SD = 2. The Z score is __________.
Answer: 4
78) Alex’s Z score on his abnormal psychology exam was −.05, indicating that he scored well
above the mean on the exam. (True or False).
Answer: FALSE
79) The formula for changing a Z score to a raw score is __________.
Answer: X = (Z)(SD) + M
80) Behaviorists such as B. F. Skinner sometimes object to the use of statistics in research
because averages can distort the pattern of information revealed from observing the
behavior of __________.
Answer: each individual case
81) List the three most widely used ways to describe a typical or representative value and
explain what each tells a researcher.
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82) Make up three sets of scores for eight people who took a verbal ability test (test ranges
from 20 to 60 points). For one set of scores, the mean should be greater than the median.
For the second set of scores, the mean and median should be equivalent. For the third set of
scores, the mode should be greater than both the mean and median.
83) Make up an example in which the median would be the preferred measure of the
representative value of a group of scores.
84) The tiger at the local zoo lived to the age of 28 while the elephant lived to the age of 65.
Explain to someone unfamiliar with statistical techniques which animal lived longer
relative to the expected lifespan of its species? Use the information provided below to help
answer the question.
Average lifespan of a tiger = 22 (SD = 3)
Average lifespan of an elephant = 70 (SD = 7)
85) Based on an analysis of personnel records, an organizational specialist reports that for her
company: “During the last year, the mean number of sick days taken by shop employees
was 7.3 with a standard deviation of 6.1.” Explain what this result means to a person who
has never had a course in statistics.
86) During the winter, a survey is conducted at a particular college regarding the number of
hours spent outside on weekends. The survey reports that for students from cold-weather
climates, M = 8, SD = 1.5. For students from warm-weather climates, M = 5, SD = 4.2.
Explain what these numbers mean and the conclusions one should draw from this study.
87) Here are the average snowfalls (in inches) for a particular northern U.S. city on consecutive
February days during the winter of 2007: 0, 0, 2, 2, 4, 5, 0, 0, 6, 15. Describe the
representative (typical) snowfall and the amount of variation in this city. Provide three
ways of describing the representative snowfall and two ways of describing its variation,
explaining differences in how you calculated each value.
88) How might researchers combine quantitative and qualitative methodologies to improve
psychological research?
89) Five high school English teachers were given a grammar test. Their scores were as follows:
17, 19, 14, 20, 20.
Figure the mean, mode, variance, and standard deviation for this sample.
Explain what you have done and what the results mean to a person who has never had a
course in statistics.
Answer: Mean = 90/5 = 18
Mode = 20
Variance = 1 + 1 + 16 + 4 + 4 = 26/5 = 5.2
Standard Deviation = square root of 5.2 = 2.28
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90) A teacher rated the reading ability level of six fourth-grade children participating in a
special math program. The ratings were as follows: 3, 3, 2, 8, 4, 4.
Figure the mean, variance, and standard deviation for this group of scores.
Explain what you have done and what the results mean to a person who has never had a
course in statistics.
Answer: Mean = 24/6 = 4
Mode = bimodal(3 and 4)
Variance = 1 + 1 + 4 + 16 + 0 + 0 = 22/6 = 3.67
Standard Deviation = square root of 3.67 = 1.92
91) A museum curator was interested in people’s responses to art. She therefore had seven
people indicate their liking for a particular piece of Egyptian sculpture. Their ratings were
as follows: 2, 4, 4, 5, 6, 7, 7.
Figure the mean, median, mode, variance, and standard deviation for this group of
scores.
Explain what you have done and what the results mean to a person who has never had a
course in statistics.
Answer: Mean = 35/7 = 5
Median = 5
Mode = bimodal(4 and 7)
Variance = 9 + 1 + 1 + 0 + 1 + 4 + 4 = 20/7 = 2.86
Standard Deviation = square root of 3.67 = 1.69
92) After attending an anxiety-reduction therapy session, a wife’s anxiety score is 75, while her
husband’s is 80. Overall, women’s average anxiety score after the sessions is 70 (SD = 10)
and men’s average anxiety score after the sessions is 85 (SD = 5).
Relative to others of their own gender, who has the lower anxiety score after the session?
Explain your answer to someone who has never had a course in statistics.
Answer: Wife’s Z = .5; Husband’s Z = −1. Thus, wife is more anxious relative to her gender.
(Note: Lower score = positive outcome/reduced anxiety. Thus, negative Z scores
indicate lower anxiety.)
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93) A business researcher has to decide which of three employees should be placed in a
particular job that requires a high level of perceptual–motor coordination. All three
employees have taken tests of perceptual–motor coordination, but each took a different
test.
Employee A scored 15 on a test with a mean of 10 and a standard deviation of 2.
Employee B scored 350 on a test with a mean of 300 and a standard deviation of 40.
Employee C scored 108 on a test with a mean of 100 and a standard deviation of 16.
On all three tests, higher scores mean greater coordination.
Which employee has the best perceptual–motor coordination?
Explain your answer to someone who has never had a course in statistics.
Answer: Employee A’s Z = 2.5; Employee B’s Z = 1.25; Employee C’s Z = .5.
Thus, Employee A has the best perceptual–motor coordination and should be
given the job.
94) A clinical psychologist administered a standard test of symptoms of three different
behavioral disorders to a new patient at a mental health clinic. On the scale that measures
Disorder F (in the general public, M = 60, SD = 8), the person’s score is 62. On the scale that
measures Disorder H (in the general public, M = 32, SD = .5), the person’s score is 34. And
on the scale that measures Disorder K (in the general public, M = 83, SD = 12), the person’s
score is 89.
For the symptoms of which disorder or disorders did this person score substantially
higher than the general public?
Explain your answer to someone who has never had a course in statistics.
Answer: Disorder F, Z = .25; Disorder H, Z = 4; Disorder K, Z = .5. Thus, only on Disorder
H are the person’s symptoms substantially higher than for the general public.
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