A feeder airline transports passengers from small cities to a single larger hub airport....

A feeder airline transports passengers from small cities to a single larger hub airport. A regression study tried to predict the revenue generated by each of 22 small cities, based on the distance of each city (in miles) from the hub and on the population of the small cities. The correlations and scatterplots were obtained as shown.

a. Are the independent variables severely correlated?

b. Do the scatterplots indicate that there may be a problem with high leverage points?