Question 1
According to the empirical rule, if the data form a bell-shaped distribution, then about _____ percent of the observations will be within plus or minus 1 standard deviations from the mean.
68
97.5
99.7
95

Question 2
Health care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years of age whose net worth is too high to qualify for Medicaid and have no private health insurance. The ages of 25 uninsured senior citizens were as follows:
60 61 62 63 64 65 66 68 68 69 70 73 73 74 75 76 76 81 81 82 86 87 89 90 92
Identify the interquartile range of the ages of the uninsured senior citizens.
17 years
16 years
14 years
15 years

Question 3
Which of the following descriptive statistics are NOT shown on a box-and-whiskers plot?
The variance.
The range.
The interquartile range.
The median.

Question 4
Which of the following statements about the median is NOT true?
It is more affected by extreme values than the arithmetic mean.
It is a measure of central tendency.
It is equal to Q2.
It is equal to the mode in bell-shaped “normal” distributions.

Question 5
Health care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years of age whose net worth is too high to qualify for Medicaid and have no private health insurance. The ages of 25 uninsured senior citizens were as follows:
60 61 62 63 64 65 66 68 68 69 70 73 73 74 75 76 76 81 81 82 86 87 89 90 92
Identify which of the following is the correct statement.
One fourth of the senior citizens sampled are below 64 years of age.
The middle 50% of the senior citizens sampled are between 65.5 and 73.0 years of age.
One quarter of the senior citizens sampled are older than 81.5 years of age.
All of the above are correct.

Question 6
Which of the following is NOT sensitive to extreme values?
The range.
The standard deviation.
The interquartile range.
The coefficient of variation.

Question 7
In left-skewed distributions, which of the following is the correct statement?
The distance from Q1 to Q2 is smaller than the distance from Q2 to Q3.
The distance from the smallest observation to Q1 is larger than the distance from Q3 to the largest observation.
The distance from the smallest observation to Q2 is smaller than the distance from Q2 to the largest observation.
The distance from Q1 to Q3 is twice the distance from the Q1 to Q2.

Question 8
Which of the following is NOT a measure of central tendency?
The arithmetic mean.
The geometric mean.
The mode.
The interquartile range.

Question 9
Which descriptive statistics are considered to be resistant statistics (i.e., less affected by extreme values)?
The arithmetic mean and standard deviation.
The interquartile range and range.
The mode and variance.
The median and interquartile range.

Question 10
A statistics student found a reference in the campus library that contained the median family incomes for all 50 states. She would report her data as being collected using
a designed experiment.
observational data.
a random sample.
a published source.

Question 11
The chancellor of a major university was concerned about alcohol abuse on her campus and wanted to find out the proportion of students at her university who visited campus bars on the weekend before the final exam week. Her advisor took a random sample of 250 students. The total number of students in the sample who visited campus bars on the weekend before the final exam week is an example of
a categorical random variable.
a discrete random variable.
a continuous random variable.
a parameter.

Question 12
Jared was working on a project to look at global warming and accessed an Internet site where he captured average global surface temperatures from 1866. Which of the four methods of data collection was he using?
Published sources
Experimentation
Surveying
Observation

Question 13
Those methods involving the collection, presentation, and characterization of a set of data in order to properly describe the various features of that set of data are called
statistical inference.
the scientific method.
sampling.
descriptive statistics.

Question 14
Researchers suspect that the average number of units earned per semester by college students is rising. A researcher at Calendula College wishes to estimate the number of units earned by students during the spring semester at Calendula. To do so, he randomly selects 100 student transcripts and records the number of units each student earned in the spring term. He found that the average number of semester units completed was 12.96 units per student. Identify the population of interest to the researcher.
All Calendula College students.
All college students.
All Calendula College students enrolled in the spring
All college students enrolled in the spring.

Question 15
The personnel director at a large company studied the eating habits of the company’s employees. The director noted whether employees brought their own lunches to work, ate at the company cafeteria, or went out to lunch. The goal of the study was to improve the food service at the company cafeteria. This type of data collection would best be considered as
an observational study.
a designed experiment.
a random sample.
a quota sample.

Question 16
The average number of units earned per semester by college students is suspected to be rising. A researcher at Calendula College wishes to estimate the number of units earned by students during the spring semester at Calendula. To do so, he randomly selects 100 student transcripts and records the number of units each student earned in the spring term. Identify the variable of interest to the researcher.
The number of students enrolled at Calendula College during the spring term.
The average indebtedness of Calendula College students enrolled in the spring.
The age of Calendula College students enrolled in the spring.
The number of units earned by Calendula College students during the spring term.

Question 17
Which of the following is not an element of descriptive statistical problems?
The population or sample of interest.
Tables, graphs, or numerical summary tools.
Identification of patterns in the data.

Question 18
A sample of 200 students at a Big-Ten university was taken after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm. The following table contains the result.
Table 2-6
Did Well in Midterm Did Poorly in Midterm
Studying for Exam80 20
Went Bar Hopping30 70
Referring to Table 2-6, if the sample is a good representation of the population, we can expect_______ percent of the students in the population to spend the weekend studying and do poorly on the midterm.
10
20
45
50

Question 19
A type of vertical bar chart in which the categories are plotted in the descending rank order of the magnitude of their frequencies is called a
contingency table.
Pareto diagram.
dot plot.
pie chart.

Question 20
At a meeting of information systems officers for regional offices of a national company, a survey was taken to determine the number of employees the officers supervise in the operation of their departments, where X is the number of employees overseen by each information systems officer.
Table 2-2
X f
1 7
2 5
3 11
4 8
5 9
Referring to Table 2-2, how many regional offices are represented in the survey results?
5
11
15
40

Question 21
A sample of 200 students at a Big-Ten university was taken after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm. The following table contains the result.
Table 2-6
Did Well in Midterm Did Poorly in Midterm
Studying for Exam80 20
Went Bar Hopping30 70
Referring to Table 2-6, if the sample is a good representation of the population, we can expect_______ percent of those who spent the weekend studying to do poorly on the midterm.
10
20
45
50

Question 22
When analyzing a single numerical variable, you may use:
a histogram
relative frequency polygon
cumulative percentage polygon
All of the above

Question 23
In a contingency table, the number of rows and columns
must always be the same.
must always be 2.
None of the above.

Question 24
The width of each bar in a histogram corresponds to the
the x-values that the bar represents.
number of observations for the x-values.
midpoint of each class.
percentage of observations in each class.

Question 25
When polygons or histograms are constructed, which axis must show the true zero or “origin”?
The horizontal axis.
The vertical axis.
Both the horizontal and vertical axes.
Neither the horizontal nor the vertical axis.