Question

A company produces electric motors for use in home appliances. One of the company’s managers is interested in examining the relationship between delivery costs in a month and the number of motors produced that month that were returned by dissatisfied customers (Y). He has collected the data in the file.Write the theoretical formula and calculate using excel the r-square of the regression equation and interpret the result.

Month	Delivery cost (k$) X	Motors_Returned Y
1	43,55	67
2	55,83	64
3	48,53	65
4	48,55	65
5	69,29	65
6	64,39	64
7	58,32	64
8	76,90	67
9	65,98	64
10	43,44	67
11	41,50	67
12	55,07	64
13	60,74	64
14	41,06	68
15	64,58	64
16	70,22	65
17	68,25	65
18	50,93	65
19	76,35	67
20	43,93	67
21	60,25	64
22	42,22	67
23	79,18	68
24	66,63	64
25	79,67	68
26	52,79	65
27	50,58	65
28	66,86	64
29	42,95	67
30	62,45	64
31	42,73	67
32	78,45	67
33	74,49	66
34	62,68	64
35	74,41	66
36	42,41	67

Answer 1

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.1341
R Square	0.0180
Adjusted R Square	-0.0109
Standard Error	1.4496
Observations	36
ANOVA
	df	SS	MS	F	Significance F
Regression	1	1.3091	1.3091	0.6230	0.4354
Residual	34	71.4409	2.1012
Total	35	72.75
	Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%
Intercept	66.477	1.157231326	57.444542	1.906E-35	64.12484698	68.8284
Delivery cost (k$) X	-0.015	0.019162413	-0.7893128	0.4353992	-0.054067847	0.023818

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by increasing one unit if x there is on an average 0.015 unit decrease in y

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By increasing one unit of x there is 1.8% variation in y