A Roofing and Siding company sells its products tohome repair retailers. The owner is
interested in studying the effects of severalvariables on the value of shingles sold ($000).
The marketing manageris arguing that the companyshpuld spend more money on Â
advertising, while a market researcher suggests itshould focus more on making its brand
and product more distinct from itscompetitors.
The company has divided the United States into 26marketing districts. In each district, it collected
information on the following variables:
		Advertising		Number
		dollars	Number of	of	Market
Obs.	Sales	(000's)	Accounts	competitors	Potential
1	79.3	5.5	31	10	8
2	200.1	2.5	55	8	6
3	163.2	8	67	12	9
4	200.1	3	50	7	16
5	146	3	38	8	15
6	177.7	2.9	71	12	17
7	30.9	8	30	12	8
8	291.9	9	56	5	10
9	160	4	42	8	4
10	339.4	6.5	73	5	16
11	159.6	5.5	60	11	7
12	86.3	5	44	12	12
13	237.5	6	50	6	6
14	107.2	5	39	10	4
15	155	3.5	55	10	4
16	291.4	8	70	6	14
17	100.2	6	40	11	6
18	135.8	4	50	11	8
19	223.3	7.5	62	9	13
20	195	7	59	9	11
21	73.4	6.7	53	13	5
22	47.7	6.1	38	13	10
23	140.7	3.6	43	9	17
24	93.5	4.2	26	8	3
25	259	4.5	75	8	19
26	331.2	5.6	71	4	9
	Conduct a multiple regression analysis to find thebest predictors of sales
a.	Draw a scatter diagram comparing sales volume witheach of the independent variables.
	Comment on the results.
b.	Develop a correlation matrix. Do you see anyproblems? Does it appear there are any
	redundant independent variables?
c.	Develop a regression equation. Conduct the globaltest. Can we conclude that some of
	the independent variables are useful in explainingthe variation in the dependent variable.
d.	Conduct a test of each of the independentvariables. Are there any that should be dropped?
e.	Refine the regression equation so the remainingvariablesare all significant.
f.	Determine the variance inflation factor for each ofthe independent variables. Are there any
	problems?

# Please I need the answer by Excel with showing steps.