Answer
Gas mileage of an automobile with 200 horsepower:
The 95% confidence interval is between 21.6220 and 23.6651 miles per gallon.
(for the mean gas mileage of all automobile with 200 horsepower)
The 95% prediction interval is between 19.2506 and 26.0364 miles per gallon.
(for the gas mileage of a particular automobile with 200 horsepower)
Work Step by Step
With the results from item (e) still available in MINITAB:
Select Stats -> Regression -> Regression -> Predict
Enter 200 in the first cell of the table.
Click in Options and enter the level of confidence. Click OK.
Click OK.
