The following data represent commute times (in minutes) and score on a well-being survey.
Commute Time Gallup-Healthways Well-Being
(minutes), x ....... Index Composite Score, y
5 .......... 69.2
15 .......... 68.3
25 .......... 67.5
35 .......... 67.1
50 .......... 66.4
72 .......... 66.1
105 .......... 63.9
(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.
(b) Interpret the slope and y-intercept, if appropriate.
(c) Predict the well-being index of a person whose commute is 30 minutes.
(d) Suppose Barbara has a 20-minute commute and scores 67.3 on the survey. Is Barbara more “well-off” than the typical individual who has a 20-minute commute?