17.
One use of a regression line is
a.
to determine if any x-values are outliers.
b.
to determine if any y-values are outliers.
c.
to determine if a change in x causes a change in y.
d.
to estimate the change in y for a one-unit change in x.
18.
Past data has shown that the regression line relating the final exam score and the midterm
exam score for students who take statistics from a certain professor is:
final exam
= 50 + 0.5
×
midterm
One interpretation of the slope is
a.
a student who scored 0 on the midterm would be predicted to score 50 on the final exam.
b.
a student who scored 0 on the final exam would be predicted to score 50 on the midterm
exam.
c.
a student who scored 10 points higher than another student on the midterm would be
predicted to score 5 points higher than the other student on the final exam.
d.
students only receive half as much credit (.5) for a correct answer on the final exam
compared to a correct answer on the midterm exam.
Questions 19 to 21:
A survey asked people how often they exceed speed limits. The data are
then categorized into the following contingency table of counts showing the relationship between
age group and response.
Exceed Limit if Possible?
Age Always Not
Always Total
Under 30
100 100 200
Over 30
40 160 200
Total
140 260 400
19.
Among people with age
over 30
, what's the "risk" of always exceeding the speed limit?
a.
0.20
b.
0.40
c.
0.33
d.
0.50
20.
Among people with age
under 30
what are the odds that they always exceed the speed limit?
a.
1 to 2
b.
2 to 1
c.
1 to 1
d.
50%
21.
What is the relative risk of always exceeding the speed limit for people under 30 compared to
people over 30?
a.
2.5
b.
0.4
c.
0.5
d.
30%