Statistics Final Exam/ 135 Qs with Definitive
Solutions.
A large state university conducted a survey among their students and received 400 responses.
The survey asked the students to provide the following information:
*Age
*Year in School (Freshman, Sophomore, Junior, Senior)
*Major
What type of graph would you use to describe the variable Major? - Answer: A bar chart
because Major is a categorical variable.
Parking at a university has become a problem. University administrators are interested in
determining the average time it takes a student to find a parking spot. An administrator
inconspicuously followed 180 students and recorded how long it took each of them to find a
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,parking spot. Which of the following types of graphs should NOT be used to display information
concerning the students parking times? - Answer: pie chart
Each day for twenty days a record store owner counts the number of customers who purchase
an album by a certain artist. The data and a dotplot of the data are shown below:
Data set: 1, 3, 4, 4, 5, 6, 7, 2, 3, 4, 4, 5, 6, 8, 2, 3, 4, 5, 6, 7, 9 - Answer: The dotplot shows that
this data has a roughly bell-shaped distribution.
The bar charts below depict the veteran statuses of Americans, separated by gender. Which bar
chart has more variability in veteran status? Why? - Answer: The male bar chart shows more
variability because there are more observations in the different categories than there are for
females.
The bar charts below depict the marital statuses of Americans, separated by gender. Which bar
chart shows more variability in marital status? Why? - Answer: The female bar chart shows
more variability because there are more observations in the different categories than there are
for males.
Before opening a new dealership, an auto manufacturer wants to gather information about car
ownership and driving habits of the local residents. The marketing manager of the company
randomly selects 1000 households from all households in the area and mails a questionnaire to
them. Of the 1000 surveys mailed, she receives 85 back. What is the problem with how the
information is gathered? - Answer: The only responses were from people who chose to send
the survey back.
Consider the following statement, "Babies who breastfeed are less likely to grow into children
with behavioral problems by the time they reach age 5 than those who receive formula milk."
Which of the following is a plausible confounding variable in this study? - Answer: The age at
which breastfeeding ends
Mother's social-economic status
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, The quality of the formula milk
A word cloud was created using the first chapter of John Green's The Fault in Our Stars. (Note
that filler words such as "the," "a/an," and "and" were excluded from the plot.)
According to the word cloud, what is the most common word in the first chapter of The Fault in
Our Stars? Why? - Answer: The most common word is "augustus" because it is the largest in
size.
Determine which of the following five variables are numerical and which are categorical.
age, gender, height, favorite candy, eye color - Answer: Age and height are numerical variables.
Gender, favorite candy, and eye color are categorical variables.
The graph below displays the number of applications for a concealed weapons permit in
Montcalm County, Michigan, for each of three years. A reporter interprets this graph to mean
that applications in 2010 are more than twice the level in 2008. Is the reporter making a correct
interpretation? - Answer: No. Although the 2010 bar is more than twice the height of the 2008,
the bars do not begin at 0 applications, so the graph does not correctly represent the data. Fifty-
five is not equal to two times the number of applications made in 2008.
What is the difference between a histogram and a relative frequency histogram? - Answer: A
histogram uses counts to record how many observations are in a data set, and a relative
histogram uses proportions.
The distributions of income in the United States is strongly skewed to the right. Which of the
following is true? - Answer: The median income is smaller than the mean income.
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Solutions.
A large state university conducted a survey among their students and received 400 responses.
The survey asked the students to provide the following information:
*Age
*Year in School (Freshman, Sophomore, Junior, Senior)
*Major
What type of graph would you use to describe the variable Major? - Answer: A bar chart
because Major is a categorical variable.
Parking at a university has become a problem. University administrators are interested in
determining the average time it takes a student to find a parking spot. An administrator
inconspicuously followed 180 students and recorded how long it took each of them to find a
Page 1 of 26
,parking spot. Which of the following types of graphs should NOT be used to display information
concerning the students parking times? - Answer: pie chart
Each day for twenty days a record store owner counts the number of customers who purchase
an album by a certain artist. The data and a dotplot of the data are shown below:
Data set: 1, 3, 4, 4, 5, 6, 7, 2, 3, 4, 4, 5, 6, 8, 2, 3, 4, 5, 6, 7, 9 - Answer: The dotplot shows that
this data has a roughly bell-shaped distribution.
The bar charts below depict the veteran statuses of Americans, separated by gender. Which bar
chart has more variability in veteran status? Why? - Answer: The male bar chart shows more
variability because there are more observations in the different categories than there are for
females.
The bar charts below depict the marital statuses of Americans, separated by gender. Which bar
chart shows more variability in marital status? Why? - Answer: The female bar chart shows
more variability because there are more observations in the different categories than there are
for males.
Before opening a new dealership, an auto manufacturer wants to gather information about car
ownership and driving habits of the local residents. The marketing manager of the company
randomly selects 1000 households from all households in the area and mails a questionnaire to
them. Of the 1000 surveys mailed, she receives 85 back. What is the problem with how the
information is gathered? - Answer: The only responses were from people who chose to send
the survey back.
Consider the following statement, "Babies who breastfeed are less likely to grow into children
with behavioral problems by the time they reach age 5 than those who receive formula milk."
Which of the following is a plausible confounding variable in this study? - Answer: The age at
which breastfeeding ends
Mother's social-economic status
Page 2 of 26
, The quality of the formula milk
A word cloud was created using the first chapter of John Green's The Fault in Our Stars. (Note
that filler words such as "the," "a/an," and "and" were excluded from the plot.)
According to the word cloud, what is the most common word in the first chapter of The Fault in
Our Stars? Why? - Answer: The most common word is "augustus" because it is the largest in
size.
Determine which of the following five variables are numerical and which are categorical.
age, gender, height, favorite candy, eye color - Answer: Age and height are numerical variables.
Gender, favorite candy, and eye color are categorical variables.
The graph below displays the number of applications for a concealed weapons permit in
Montcalm County, Michigan, for each of three years. A reporter interprets this graph to mean
that applications in 2010 are more than twice the level in 2008. Is the reporter making a correct
interpretation? - Answer: No. Although the 2010 bar is more than twice the height of the 2008,
the bars do not begin at 0 applications, so the graph does not correctly represent the data. Fifty-
five is not equal to two times the number of applications made in 2008.
What is the difference between a histogram and a relative frequency histogram? - Answer: A
histogram uses counts to record how many observations are in a data set, and a relative
histogram uses proportions.
The distributions of income in the United States is strongly skewed to the right. Which of the
following is true? - Answer: The median income is smaller than the mean income.
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