STATISTICS COMPREHENSIVE EXAM SCRIPT
2026 SOLVED QUESTIONS WITH CORRECT
ANSWERS
◉ (Module 6) A confidential and voluntary survey conducted in STA
3024 in the Spring of 1999 asked the students questions about their
sex life. A simple linear regression analysis was conducted to predict
the number of lifetime sexual partners a student has had based on
the number of sexual partners the student has had in the past year.
The analysis yielded an R-squared of 27.8%. Interpret R-squared.
a. 27.8% of the variability in the student's number of sexual partners
in the past year is explained by the number of lifetime sexual
partners the student has had.
b. 27.8% of the variability in the number of sexual partners students
have had in their lifetime is explained by the number of sexual
partners in the past year.
c. As the student's number of lifetime sexual partners increases by
one, the number of sexual partners in the past year increases by
27.8%.
d. As the student's number of sexual partners in the past year.
Answer: b. 27.8% of the variability in the number of sexual partners
students have had in their lifetime is explained by the number of
sexual partners in the past year.
,◉ (Module 6) A political scientist was interested in studying
America's voting habits. So, he decided to make a least squares
regression equation to predict the percentage of people in a state
that would vote for Obama in 2012 based on the percentage of
people in a state that voted for Obama in 2008. The least squares
equation is y-hat = -4.599 +1.04x. In the state of Alabama, 37.74%
voted for Obama in 2008; whereas, 38.35% voted for him in 2012.
What is the value of the residual?
a. 34.65
b. 3.70
c. -3.70
d. 4.02
e. -4.02. Answer: b. 3.70
◉ (Module 7) People who use artificial sweeteners in place of sugar
tend to be heavier than people who use sugar, thus we can conclude
that artificial sweeteners are detrimental to weight loss efforts. This
is an example of:
a. extrapolation
b. misuse of cause and effect
c. influential outlier. Answer: b. misuse of cause and effect
, ◉ (Module 7) A study found a strong positive correlation between
ice cream consumption and the number of violent crimes committed
each month.Some people may take this as an indication of how
refined sugars make people violent. This is an example of:
a. extrapolation
b. misuse of cause and effect
c. influential outlier. Answer: b. misuse of cause and effect
◉ (Module 7) A high positive correlation is found between college
students' age and their GPA. However, if one student aged 44 with a
high GPA is omitted from the study, the correlation all but
disappears. This is an example of:
a. extrapolation
b. misuse of cause and effect
c. influential outlier. Answer: b. misuse of cause and effect
◉ (Module 8) A researcher for Coca-Cola is testing new flavors for
an energy drink:lemon-lime, grape, strawberry and orange. Each
participant tries each of the flavors and states which they like the
best. What would be the appropriate graph to make of the sampled
data?