p.591 Problem 41

Management of a home appliance store would like to understand the growth pattern of the monthly sales of Blu- ray disc players over the past two years. Managers have recorded the relevant data in the file P10_ 09. xlsx.
a. Create a scatterplot for these data. Comment on the observed behavior of monthly sales at this store over time.
b. Estimate an appropriate regression equation to explain the variation of monthly sales over the given time period. Interpret the estimated regression coefficients.
c. Analyze the estimated equation’s residuals. Do they suggest that the regression equation is adequate? If not, return to part b and revise your equation. Continue to revise the equation until the results are satisfactory.

2

>Source

This is fictitious data.

Data

2

3

2

5

0

6

56

7

00

8

9

66

12

1

20

23

24

Month	Blu-ray disc players sold
1	2	3
1	5	6
330
4	4	8
	12	9
1	7
	20
2512
	23
10	2942
11	2872
2937
13	3136
14	3	24
15	3149
16	3524
17	3542
18	3312
19	3547
3376
21	3375
22	3403
3697
3495