Regression Revisited

 Practice Problems

The file http://inspire.stat.ucla.edu/unit_14/cars.txt contains information on price, horse power, and gas mileage for a random sample of vehicle models commonly sold in the United States. You will use this data for the practice problems.
 
1. Test the hypothesis that horse power is a useful linear predictor of gas mileage. Be use you check the necessary conditions for the hypothesis test.
2. Find and interpret a 95% confidence interval for the slope relevant to Question 1.
3. Find and interpret a 95% confidence interval for the slope for predicting price from horse power, if this is reasonable. If not, explain why not.

Care to check your answers?