STT 231 Practice Exam CORRECT 100%
The type of aircraft - ANSWERCategorical
The flight number (e.g., Flight 1013). - ANSWERCategorical
The number of passengers. - ANSWERQuantitative
Whether the flight departed and arrived on schedule. - ANSWERCategorical
The number of luggage each passenger checks for flight - ANSWERNot a variable with
respect to these observational units
Aspirin and Cancer~ Aspirin, the medicine commonly used for headache and fever, has
been shown to reduce the risk of stroke and heart attack in susceptible people.
Observational studies have suggested that aspirin may also reduce the risk of cancer.
500 volunteer women participated in a carefully designed experimental study to test the
role of aspirin on reducing the risk of cancer The table below summarizes some of the
study results. Use these results to answer the following questions.
Which of the following terms applies to the variable 'cancer status' in this study? Circle
all that apply - ANSWERcategorical and response
Among those participants that used aspirin, what is the probability of getting cancer?
(You may leave your answer as a fraction.) - ANSWER30/250
What is the probability that a randomly selected participant took aspirin and got cancer?
(You may leave your answer as a fraction.) - ANSWER30/500
Consider the mosaic plot to the right, which summarizes the study results. Are the
events 'took aspirin' and 'get cancer' independent? Clearly circle 'yes' or 'no' and provide
a brief written support. - ANSWERYes. the proportion of observations in the aspirin
group who got cancer is almost identical to the proportion in the " no cancer" group
Consider the following graph, which displays the distribution of text messages sent in
the last hour by a sample of 10students enrolled in a large introductory statistics course.
The mean of this distribution is 𝑥̅ = 11.0 text messages, the median is 𝑥̃ = 9.5 text
messages, and the standard deviation is 𝑠 = 6 text messages. - ANSWERThe mean,
median, and standard deviation all increase. Draw this data point on the graph above
and label it (A).
Is the mid-range a measure of center or a measure of variability? - ANSWERcenter
Consider two new statistics that we have not yet studied:
The type of aircraft - ANSWERCategorical
The flight number (e.g., Flight 1013). - ANSWERCategorical
The number of passengers. - ANSWERQuantitative
Whether the flight departed and arrived on schedule. - ANSWERCategorical
The number of luggage each passenger checks for flight - ANSWERNot a variable with
respect to these observational units
Aspirin and Cancer~ Aspirin, the medicine commonly used for headache and fever, has
been shown to reduce the risk of stroke and heart attack in susceptible people.
Observational studies have suggested that aspirin may also reduce the risk of cancer.
500 volunteer women participated in a carefully designed experimental study to test the
role of aspirin on reducing the risk of cancer The table below summarizes some of the
study results. Use these results to answer the following questions.
Which of the following terms applies to the variable 'cancer status' in this study? Circle
all that apply - ANSWERcategorical and response
Among those participants that used aspirin, what is the probability of getting cancer?
(You may leave your answer as a fraction.) - ANSWER30/250
What is the probability that a randomly selected participant took aspirin and got cancer?
(You may leave your answer as a fraction.) - ANSWER30/500
Consider the mosaic plot to the right, which summarizes the study results. Are the
events 'took aspirin' and 'get cancer' independent? Clearly circle 'yes' or 'no' and provide
a brief written support. - ANSWERYes. the proportion of observations in the aspirin
group who got cancer is almost identical to the proportion in the " no cancer" group
Consider the following graph, which displays the distribution of text messages sent in
the last hour by a sample of 10students enrolled in a large introductory statistics course.
The mean of this distribution is 𝑥̅ = 11.0 text messages, the median is 𝑥̃ = 9.5 text
messages, and the standard deviation is 𝑠 = 6 text messages. - ANSWERThe mean,
median, and standard deviation all increase. Draw this data point on the graph above
and label it (A).
Is the mid-range a measure of center or a measure of variability? - ANSWERcenter
Consider two new statistics that we have not yet studied:
