Martin Company purchases a machine at the beginning of the year at a cost of $90,000. The machine is depreciated using the double-declining-balance method. The machine's useful life is estimated to be 4 years with a $7,500 salvage value. The machine's book value at the end of year 3 is: Xo1:29:28 Multiple Choice o $67,500. o $45,000. o $78,750. o $11,250. c $10,313