E11-5B (Lol, 2) (Depreciation Computations-Four Methods) Foster Corporation purchased a new machine for its assem- bly process on August 1, 2017, The cost of this machine was $235,800. The company estimated that the machine would have a trade-in value of $25,800 at the end of its service life. Its life is estimated at 10 years, and its working hours are estimated at 42,000 hours. Year-end is December 31 Instructions Compute the depreciation expense under the following methods. Each of the following should be considered unrelated. (a) Straight-line depreciation for 2017. (b) Activity method for 2017, assuming that machine usage was 800 hours (c) Sum-of-the-years'-digits for 2018. (d) Double-declining balance for 2018