Problem 9-2A (Part Level Submission) In recent years, Swifty Transportation purchased three used buses. Because of frequent turnover in the accounting department, a different accountant selected the depreciation method for each bus, and various methods were selected. Information concerning the buses is shown as follows. Useful Life in Years Depreciation Method Bus Cost Acquired 1/1/17 + Salvage Value $ 7,500 10,000 8,000 2 $ 99,400 118,000 82,400 1/1/17 + Straight-line Declining-balance Units-of-activity 3 1/1/18 + For the declining-balance method, the company uses the double-declining rate. For the units-of-activity method, total miles are expected to be 120,000. Actual miles of use in the first 3 years were 2018, 27,000; 2019, 31,500; and 2020, 31,500. (a1) For Bus #3, calculate depreciable cost per mile under units-of-activity method. (Round answer to 2 decimal places, e.g. 0.50.) Depreciable cost per mile