Whispering Winds Bus Lines uses the units-of-activity method in depreciating its buses. One bus was purchased on January 1, 2022, at a cost of $243,161. Over its 7-year useful life, the bus is expected to be driven 147,900 miles. Salvage value is expected to be $8,000. (a) Compute the depreciable cost per unit. (Round answer to 2 decimal places, e.g. 0.50.) Depreciation cost per unit ta $ per mile