Question

Cincinnati Paint Company sells quality brands of paints through hardware stores throughout the United States. The company maintains a large sales force who call on existing customers and 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 ($000)	Calls	Driven	Commissions ($000)	Calls	Driven
19	140	2,374	37	147	3,293
11	133	2,227	43	146	3,106
33	146	2,732	26	150	2,127
38	143	3,354	39	146	2,793
25	145	2,292	35	152	3,211
44	144	3,451	12	132	2,290
29	139	3,114	32	148	2,852
39	139	3,347	25	135	2,693
39	145	2,843	27	132	2,935
29	134	2,627	22	129	2,671
22	139	2,123	40	158	2,991
12	139	2,224	35	148	2,834
46	149	3,465

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

Commissions =

+

Calls +

Miles +

x1x2

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

Predictor	Coefficient	SE Coefficient	t	p-value
Constant
Calls
Miles
X1X2

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

Value of the test statistic

At the 0.05 significance level is there a significant interaction between the number of sales calls and the miles driven?

This is

, so we conclude that there

.

Answer 1