In: Statistics and Probability
The data below represent commute times (in minutes) and scores on a well-being survey. Complete parts (a) through (d) below. Commute Time (minutes), x 5 15 30 40 50 84 105 Well-Being Index Score, y 68.9 67.6 65.8 64.9 64.0 61.5 58.8 (a) Find the least-squares regression line treating the commute time, x, as the explanatory variable and the index score, y, as the response variable. ModifyingAbove y with caret equalsnothingxplusleft parenthesis nothing right parenthesis (Round to three decimal places as needed.) (b) Interpret the slope and y-intercept, if appropriate. Interpret the slope. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A.
For every unit increase in commute time, the index score
falls
by
nothing
,
on average.
(Round to three decimal places as needed.)
B.
For an index score of zero, the commute time is predicted to be
nothing
minutes.
(Round to three decimal places as needed.)
C.
For every unit increase in index score, the commute time
falls
by
nothing
,
on average.
(Round to three decimal places as needed.)
D.
For a commute time of zero minutes, the index score is predicted to be
nothing
.
(Round to three decimal places as needed.)
E.
It is not appropriate to interpret the slope.
Interpret the y-intercept. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A.
For an index score of zero, the commute time is predicted to be
nothing
minutes.
(Round to three decimal places as needed.)
B.
For every unit increase in commute time, the index score
falls
by
nothing
,
on average.
(Round to three decimal places as needed.)
C.
For a commute time of zero minutes, the index score is predicted to be
nothing
.
(Round to three decimal places as needed.)
D.
For every unit increase in index score, the commute time
falls
by
nothing
,
on average.
(Round to three decimal places as needed.)
E.
It is not appropriate to interpret the y-intercept.
(c) Predict the well-being index of a person whose commute time is
25
minutes.
The predicted index score is
nothing
.
(Round to one decimal place as needed.)
(d) Suppose Barbara has a
20
-minute
commute and scores
66.2
on the survey. Is Barbara more "well-off" than the typical individual who has a
20
-minute
commute? Select the correct choice below and fill in the answer box to complete your choice.
(Round to one decimal place as needed.)
A.
Yes, Barbara is more well-off because the typical individual who has a
20
-minute
commute scores
nothing
.
B.
No, Barbara is less well-off because the typical individual who has a
20
-minute
commute scores
nothing
.
(a) Find the least-squares regression line treating the commute time, x, as the explanatory variable and the index score, y, as the response variable
The least square regression equation is
Y=68.9921-0.0955X
(b) Interpret the slope and y-intercept, if appropriate. Interpret the slope. Select the correct choice below and, if necessary, fill in the answer box to complete your choice
For every unit increase in commute time, the index score falls by 0.095 on avearge.(option a is correct)
(c) Interpret the y-intercept. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
sol;
(c) Predict the well-being index of a person whose commute time is 25
sol:Y=68.9921-0.0955X
Y=68.9921-0.0955(25)
Y=68.9921-2.3875
Y=66.60
The predicted index score is 66.6