Question

Cincinnati Paint Company sells quality brands of paints through hardware stores throughout the United States. The company maintains a large sales force whose job it is to call on existing customers as well as look for new business. The national sales manager is investigating the relationship between the number of sales calls made and the miles driven by the sales representative. Also, do the sales representatives who drive the most miles and make the most calls necessarily earn the most in sales commissions? To investigate, the vice president of sales selected a sample of 25 sales representatives and determined:

The amount earned in commissions last month (Y).

The number of miles driven last month (X1)

The number of sales calls made last month (X2)

Commissions	Calls	Driven
23	141	2374
13	132	2229
34	145	2734
39	144	3351
24	142	2292
48	142	3451
29	141	3116
39	141	3342
42	146	2843
32	138	2625
21	138	2123
14	140	2223
47	149	3464
38	150	3291
45	146	3104
29	148	2124
38	146	2793
38	149	3209
14	133	2289
35	148	2852
25	135	2691
28	134	2934
26	131	2673
44	156	2991
34	150	2830

Click here for the Excel Data File

Develop a regression equation including an interaction term. (Round your answers to 3 decimal places. Negative amounts should be indicated by a minus sign.)

A.) Commissions =_______ +________ Calls +________ Miles +______ X1X2

B.) Complete the following table. (Round your answers to 3 decimal places. Negative amounts should be indicated by a minus sign.)

Predictor Coefficient    SE Coefficient    T P-value

Constant _______         __________    ___   _________

Calls

Miles

X1X2

C.) Compute the value of the test statistic corresponding to the interaction term. (Round your answer to 2 decimal places. Negative amount should be indicated by a minus sign.)

Answer 1

A)Develop a regression equation including an interaction term

Commissions = - 380.086 +2.589 Calls + 0.1158 Miles -0.00070 X1X2

B.) Complete the following table

-1.7099

Predictor	Coefficients	Standard Error	t Stat	P-value
Constant	-380.0864627	161.8206182	-2.34881	0.0287
Calls	2.589941507	1.139317248	2.27324	0.03363
Driven	0.115851058	0.05871038	1.973264	0.06177
X1X2	-0.000703341	0.000411333	-1.7099	0.10202

C.) Compute the value of the test statistic corresponding to the interaction term.

value of the test statistic = -1.71

At the 0.05 significance level is there a significant interaction between the number of sales calls