5-9. A new six-speed automatic transmission for automobiles offers an estimated 4%

improvement in fuel economy compared to traditional four-speed transmissions in front-wheel drive cars. If a four-speed transmission car averages 40 miles per gallon and gasoline costs $5.00 per gallon, how much extra can a motorist pay for a fuel-efficient six-speed transmission?

Assume that the car will be driven for 120,000 miles over its lifetime of 12 years. The motorist can earn 8% per year on investments. (5.3)