Units-of-activity depreciation A truck acquired at a cost of $69,000 has an estimated residual value of $12,000, has an estimated useful life of 300,000 miles, and was driven 77,000 miles during the year. Determine the following. If required, round your answer for the depreciation rate to 2 decimal places. (a) (b) (c) The depreciable cost The depreciation rate The units-of-activity depreciation for the year