You are the accountant for Raleigh Industries, a manufacturer of plastic gears for electric motors. The company's production facility in Pittsburgh has a cost of $3,200,000, an estimated residual value of $300,000, and an estimated useful life of 40 years. You are using the straight-line method of depreciation for this asset. (a) What is the amount of the annual depreciation (in $)? $ (b) What is the book value (in $) of the property at the end of the 20th year of use? (c) If at the start of the 21st year you revise your estimate so that the remaining useful life is 15 years and the residual value is $130,000, what should be the depreciation expense (in $) for each of the remaining 15 years?