Revision of Depreciation Equipment with a cost of $448,000 has an estimated residual value of $48,000, has an estimated useful life of 32 years, and is depreciated by the straight-line method. a. Determine the amount of the annual depreciation. $ b. Determine the book value at the end of the 15 full years of use. $ c. Assuming that at the start of the year 16 the remaining life is estimated to be 24 years and the residual value is estimated to be $42,100, determine the depreciation expense for each of the remaining 24 years