SCENARIO 18-6 A weight-loss clinic wants to use regression analysis to build a model for weight-loss of a client (measured in pounds).Two variables thought to affect weight-loss are client's length of time on the weight loss program and time of session.These variables are described below: Y = Weight-loss (in pounds) = Length of time in weight-loss program (in months) = 1 if morning session, 0 if not = 1 if afternoon session, 0 if not (Base level = evening session) Data for 12 clients on a weight-loss program at the clinic were collected and used to fit the interaction model: Partial output from Microsoft Excel follows:
-Referring to Scenario 18-6, in terms of the in the model, give the mean change in weight-loss (Y)for every 1 month increase in time in the program ( when attending the afternoon session.

Question

SCENARIO 18-6 A weight-loss clinic wants to use regression analysis to build a model for weight-loss of a client (measured in pounds).Two variables thought to affect weight-loss are client's length of time on the weight loss program and time of session.These variables are described below: Y = Weight-loss (in pounds)  = Length of time in weight-loss program (in months)  = 1 if morning session, 0 if not  = 1 if afternoon session, 0 if not (Base level = evening session) Data for 12 clients on a weight-loss program at the clinic were collected and used to fit the interaction model:  Partial output from Microsoft Excel follows: 
-Referring to Scenario 18-6, in terms of the  in the model, give the mean change in weight-loss (Y)for every 1 month increase in time in the program (  when attending the afternoon session.

Quizplus · Accepted Answer

From the given model, we can see that the coefficient for the interaction term between time in program and afternoon session (11ebc114_12e2_c50d_8acb_1f2132de5c95_TB8562_11) is 11ebc114_12e2_eb20_8acb_6f842b1269e1_TB8562_11. This means that for every one unit increase in time in program when attending the afternoon session, the mean change in weight-loss (Y) increases by 11ebc114_12e2_eb20_8acb_6f842b1269e1_TB8562_11 pounds. The coefficient for the 11ebc114_12e2_c50d_8acb_1f2132de5c95_TB8562_11 in the model is -2.5, which means that for every 1 month increase in time in the program, the mean weight-loss (Y) decreases by 2.5 pounds. The coefficient for the afternoon session variable (11ebc114_12e2_c50e_8acb_391a58eff2a4_TB8562_11) is 3.2, which means that attending an afternoon session (compared to the base level of evening session) increases the mean weight-loss (Y) by 3.2 pounds. Therefore, the mean change in weight-loss (Y) for every 1 month increase in time in the program when attending the afternoon session is -2.5 + 3.2 = 0.7 pounds increase.

SCENARIO 18-6 a Weight-Loss Clinic Wants to Use Regression Analysis