Revision of Depreciation Equipment with a cost of $680,100 has an estimated residual value of $61,800, has an estimated useful We of 27 years, and is deprecated by the straight line method a. Determine the amount of the annual depredation. b. Determine the book value after 17 full years of use. c. Assuming that at the start of the year 18 the remaining life is estimated to be 15 years and the residual value is estimated to be $53,800, determine the depreciation expense for each of the remaining 15 years