Question

The following data represent the number of flash drives sold per day at a local computer shop and their prices. Price (x) Units Sold (y) 34 36 32 35 30 38 40 4 Refer to Case 2 data use Excel, Data Analysis, Regression tools and develop a least-squares regression line and explain what the slope of the line indicates y-esimated 29.7857 0.7286x The slope indicates that as the price goes up by $1, the number of units sold goes up by 0.7286 units. y-estimated 29.7857+0.7286x. The slope indicates that as the price goes up by $1, the number of units sold goes down by 0.7286 units. y-esimated 29.7857-0.7286x The slope indicates that as the price goes up by $1, the number of units sold goes down by 0.7286 units. None of these alternatives is correct

Answer 1

Y- estimate = 29.7857- 0.7286 x

The slope indicates that as the price goes up by $1, the number of units sold goes down by 0.7286 units.

First option ($r^2 = 0.8556$.......)

x	y			SUMMARY OUTPUT
34.0000	3.0000
36.0000	4.0000			Regression Statistics
32.0000	6.0000			Multiple R	0.9250
35.0000	5.0000			R Square	0.8556
30.0000	9.0000			Adjusted R Square	0.8267
38.0000	2.0000			Standard Error	1.1199
40.0000	1.0000			Observations	7.0000
				ANOVA
					df	SS	MS	F	Significance F
				Regression	1.0000	37.1571	37.1571	29.6241	0.0028
				Residual	5.0000	6.2714	1.2543
				Total	6.0000	43.4286
					Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%	Lower 95.0%	Upper 95.0%
				Intercept	29.7857	4.7042	6.3318	0.0014	17.6933	41.8782	17.6933	41.8782
				x	-0.7286	0.1339	-5.4428	0.0028	-1.0727	-0.3845	-1.0727	-0.3845

F = 29.624> 16.26 , p-value = 0.0028 < alpha reject Ho, x and y related. t = -5.4428, p-value = 0.0028 < alpha reject Ho, x and y related