Problem 11-2 The cost of equipment purchased by Sheridan, Inc., on June 1, 2017, is $91,670. It is estimated that the machine will have a $5,150 salvage value at the end of its service life. Its service life is estimated at 7 years, its total working hours are estimated at 43,260, and its total production is estimated at 540,750 units. During 2017, the machine was operated 6,180 hours and produced 56,650 units. During 2018, the machine was operated 5,665 hours and produced 49,440 units. Compute depreciation expense on the machine for the year ending December 31, 2017, and the year ending December 31, 2018, using the following methods. (Round depreciation per unit to 2 decimal places, e.g. 15.25 and final answers to 0 decimal places, e.g. 45,892.) 2017 2018 (a) Straight-line $ $ (b) Units-of-output $ $ (c) Working hours $ $ (d) Sum-of-the-years'-digits $ $ (e) Double-declining-balance (twice the straight-line rate) $ $