One of the editors of a major automobile publication has collected data on 30 of the best-selling cars in the United States. The data are in a file called Automobiles . The editor is particularly interested in the relationship between highway mileage and curb weight of the vehicles.
a. Develop a scatter plot for these data. Discuss what the plot implies about the relationship between the two variables. Assume that you wish to predict highway mileage by using vehicle curb weight.
b. Compute the correlation coefficient for the two variables and test to determine whether there is a linear relationship between the curb weight and the highway mileage of automobiles.
c. (1) Compute the linear regression equation based on the sample data. (2) A CTS Sedan weighs approximately 4,012 pounds. Provide an estimate of the average highway mileage you would expect to obtain from this model.