Question

In testing 9 sedans, an automotive publication rated each on 13 different characteristics, including ride, handling, and driver comfort. Each vehicle also received an overall rating. Scores for each vehicle were as follows

A. . Determine the slope of Ride of least-squares multiple regression equation. (Specify your answer to 3rd decimal point)

b. Determine the slope of Handling of least-squares multiple regression equation. (Specify your answer to 3rd decimal point)

c. Determine the slope of Comfort of least-squares multiple regression equation. (Specify your answer to 2nd decimal point)

d. What is the estimated overall rating for a vehicle that scores 6 on ride, 9 on handling, and 7 on driver comfort? (Specify your answer to 3rd decimal point)

e. Determine the upper limit of 95% confidence interval. (Specify your answer to 3rd decimal point)

f. Determine the lower limit of 95% confidence interval. (Specify your answer to 3rd decimal point)

g. Determine the upper limit of 95% prediction interval. (Specify your answer to 3rd decimal point)

h. Determine the lower limit of 95% confidence interval. (Specify your answer to 3rd decimal point)

car	y=Overall rating	x1 = Ride	x2 = Handling	x3 = Driver comfort
1	85	8	7	7
2	88	8	8	8
3	85	6	8	7
4	85	8	7	9
5	97	9	9	9
6	86	8	8	9
7	90	9	6	9
8	84	7	8	7
9	94	8	9	8

Answer 1

Sol:

in excel instal analysis toolpak and then go to

Data>Data analysis>Regression

You get

From output

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.869627
R Square	0.75625
Adjusted R Square	0.61
Standard Error	2.858028
Observations	9
ANOVA
	df	SS	MS	F	Significance F
Regression	3	126.7139362	42.23798	5.170948098	0.05428
Residual	5	40.84161932	8.168324
Total	8	167.5555556
	Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%
Intercept	37.62642	13.4183161	2.804109	0.037809909	3.133541	72.1193
x1 = Ride	3.675426	1.638912028	2.242601	0.074969511	-0.53753	7.888384
x2 = Handling	2.892045	1.055396771	2.740245	0.040780193	0.179062	5.605029
x3 = Driver comfort	-0.11009	1.624691264	-0.06776	0.948604685	-4.28649	4.066317

We get

y=37.62642+3.675426*x1+2.892045*x2-0.11009*x3

Solution-A:

slope of Ride=3.675

Solution-B:

slope of Handling=2.892

Solution-C:

slope of Comfort=-0.11

Solution-D:

we have

overall rating=37.62642+3.675426*x1+2.892045*x2-0.11009*x3

hat scores 6 on ride, 9 on handling, and 7 on driver comfort

so

overall rating=37.62642+3.675426*6+2.892045*9-0.11009*7

=84.93675

=84.937

ANSWER:

estimated overall rating=84.937