Companies in the U. S. car rental market vary greatly in terms of the size of the fleet, the number of locations, and annual revenue. In 2011, Hertz had 320,000 cars in service and annual revenue of approximately $4.2 billion. Suppose the following data show the number of cars in service (1,000s) and the annual revenue ($ millions) for six smaller car rental companies.

Company Cars(1000s) Revenue ($millions)
U-Save Auto Rental System, Inc. 11.5 118
Payless Car Rental System, Inc. 10.0 135
ACE Rent A Car 9.0 100
Rent-A-Wreck of America 5.5 37
Triangle Rent-A-Car 4.2 40
Affordable/Sensible 3.3 32

(a) Use the least squares method to develop the estimated regression equation.
(b) For every additional car placed in service, estimate how much annual revenue will change.
(c) Fox Rent A Car has 11,000 cars in service. Use the estimated regression equation developed in part (c) to predict annual revenue for Fox Rent A Car.