Concord Bus Lines uses the units-of-activity method in depreciating its buses. One bus was purchased on January 1, 2022, at a cost of $279,842. Over its 7-year useful life, the bus is expected to be driven 162,600 miles. Salvage value is expected to be $8,300. (a) Compute the depreciable cost per unit. (Round answer to 2 decimal places, es. 0.50.) Depreciation cost per unit per mile