Kristen Lu purchased a used automobile for $8,000 at the beginning of last year and incurred the following operating costs: Depreciation ($8,000 5 years) $ 1,600 Insurance $ 1,200 Garage rent $ 360 Automobile tax and license $ 40 Variable operating cost $ 0.14 per mile The variable operating cost consists of gasoline, oil, tires, maintenance, and repairs. Kristen estimates that, at her current rate of usage, the car will have zero resale value in five years, so the annual straight-line depreciation is $1,600. The car is kept in a garage for a monthly fee