Question

Consider the relationship between the number of bids an item on eBay received and the item's selling price. The following is a sample of 5 items sold through an auction.

Price in Dollars	109	109	132	139	194
Number of Bids	13	13	15	19	20

A. Calculate the sum of squared errors (SSE). Use the values b0=4.5256b0=4.5256 and b1=0.0840b1=0.0840 for the calculations. Round your answer to three decimal places.\

B. Calculate the estimated variance of errors, s2e. Round your answer to three decimal places.

C. Calculate the estimated variance of slope, s2b1. Round your answer to three decimal places.

D. Construct the 90%confidence interval for the slope. Round your answers to three decimal places. Lower endpoint: ____ Upper endpoint: ________

E. Construct the 95%confidence interval for the slope. Round your answers to three decimal places. Lower endpoint: ____ Upper endpoint: ________

Answer 1

using excel>data>data analysis>Regression

we have

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.88148
R Square	0.777006
Adjusted R Square	0.702675
Standard Error	1.808474
Observations	5
ANOVA
	df	SS	MS	F	Significance F
Regression	1	34.18827	34.18827	10.45328	0.0481
Residual	3	9.811731	3.270577
Total	4	44
	Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%	Lower 90.0%	Upper 90.0%
Intercept	4.52551	3.639997	1.243273	0.302075	-7.05858	16.1096	-4.04073	13.09175
price in dollars	0.084001	0.025981	3.233154	0.0481	0.001317	0.166684	0.022858	0.145143

A. the sum of squared errors (SSE) is 9.812

B. the estimated variance of errors, s2e is 1.808*1.808 =3.269

C. the estimated variance of slope, s2b1 is 0.026*0.026 = 0.000676

D. the 90%confidence interval for the slope

. Lower endpoint: 0.023 Upper endpoint: 0.145

E. the 95%confidence interval for the slope.

. Lower endpoint: 0.001 Upper endpoint: 0.167