5. The following study discusses the efforts to reduce body weights of 20 moderately overweight student volunteers by interventions involving diet, increased physical activity, or both. The students are randomly assigned to four groups: Group 1: controls; no change in diet or physical activity Group 2: diet; reduction in caloric intake Group 3: physical activity; increase in leisure-time activity level Group 4: diet plus physical activity; receive both the interventions of group 2 and of group 3 After 3 months, weight reduction is measured, with the following results, positive values, for example, 4 indicating a 4-lb weight loss: Group 1 (controls): Group 2 (diet only): 5-2320 284 12 4 Group 3 (physical activity only): 80 2 6 2 Group 4 (both): 12 6 15 8 10 a) Does this data suggest a significant difference between groups? (Done by hand, show all your work!) b) Verify your work in part a) using SAS. (print off your SAS code and output and highlight key values. State why this verifies part a).) c) If appropriate, use a Multiple Comparison procedure taught in lecture that has the highest statistical power. (Complete by hand) d) If appropriate, show the Multiple Comparison procedure done in part c) using SAS. (print off your SAS code and output and highlight key values. Explain why this verifies part c) ) e) Notice that some groups receive a diet and others do not. Construct this contrast to see if there is a significant difference, perform the significance test, and summarize the results. (This must be done by hand).