In the effort to improve gas mileage in their vehicles a domestic carmaker collected data on the weight in pounds (000s) and miles driven per gallon of fuel.

a. Compute the model. Which do you perceive should be the dependent variable? Defend your answer.

b. Estimate the conditional mean interval at 95% if weight is 3.2.
Interpret the results.

c. What is the 95% predictive interval for weight of 3.2 and why does it differ from the conditional mean interval?

d. What portion of the change in mileage is explained by changes in weight?

e. Test the hypothesis for the regression coefficient at the 1% level of significance. What do you find?

f. Test the hypothesis for the correlation coefficient at the 1% level of significance. What do you find?

g. How significant is the hypothesis test?

Transcribed Image Text:

Weight (X) 2.2 3.6 1.6 4.2 3.9 3.5 4.6 3.8 2.5 1.6 5.3 MPG (Y) 39.6 36.2 41.1 37.2 36.2 38.5 37 35.2 39.3 40.2 36.2