The director of a training program for a large insurance company has the business objective of determining which training method is best for training underwriters. The three methods to be evaluated are classroom, online, and courseware app. The 30 trainees are divided into three randomly assigned groups of 10. Before the start of the training, each trainee is given a proficiency exam that measures mathematics and computer skills. At the end of thetraining, all students take the same end-of-training exam. Develop a multiple regression model to predict the score on theend-of-training exam, based on the score on the proficiency exam and the method of training used. Complete parts a through f below.

a. State the multiple regression equation. Use proficiency exam score as X1. Define the dummy variable X2 as X2 = 1 if the training method is classroom, X2 = 0 otherwise. Define the dummy variable X3 as X3 = 1 if the training method is online, X3 = 0 otherwise.

b. Interpret the regression coefficients in a.

c. At the 0.05 level of significance, determine whether each independent variable makes a contribution to the regression model.

d. Construct and interpret a 95% confidence interval estimate of the population slope foe the relationship between the endoftraining exam score and the proficiency exam score.

e. Add interaction terms to the model and, at the 0.05 level of significance, determine whether any interaction terms make a significant contribution to the model.

f. On the basis of the results of c and e, which model is more appropriate?

End_of_Training Proficiency Method
14 94 classroom
18 96 classroom
18 97 classroom
39 101 classroom
40 101 classroom
26 105 classroom
41 110 classroom
28 110 classroom
36 111 classroom
65 130 classroom
37 79 online
35 85 online
43 90 online
44 97 online
61 97 online
62 112 online
93 115 online
74 117 online
76 120 online
79 119 online
55 92 courseware_app
53 95 courseware_app
54 100 courseware_app
52 102 courseware_app
34 102 courseware_app
47 104 courseware_app
57 106 courseware_app
55 109 courseware_app
41 111 courseware_app
80 117 courseware_app