An Unhealthy Commute The Gallup Organization regularly surveys adult Americans regarding their commute time to work. In addition, they administer a Well-Being Survey. According to the Gallup Organization, "The Gallup-Healthways Well-Being Index Composite Score is comprised of six sub-indices: Life Evaluation, Emotional Health, Physical Health, Healthy Behavior, Work Environment and Basic Access." A complete description of the index can be found at http://www.well-beingindex.com/. The data in the following table are based on the results of the survey, which represent commute time to work (in minutes) and well-being index score. Commute Time (in minutes) Gallup-Healthways Well-Being Index Composite Score 5 69.2 15 68.3 25 67.5 35 67.1 50 66.4 72 66.1 105 63.9 Source: The Gallup Organization (a) Which variable do you believe is likely the explanatory variable and which is the response variable? (b) Draw a scatter diagram of the data. (c) Determine the linear correlation coefficient between commute time and well-being index score. (d) Does a linear relation exist between the commute time and well-being index score?