Robert Parish Corporation purchased a new machine for its assernbly process on August 1; The cost of this machine was 5117,900. The company estimated that the machine would h salvage value of S12,900 at the end of its service life. Its life is estimated at 5 years and its working hours are estimated at 21,000 hours. Year-end is December 31. Instructions Cornpute the depreciation expense under the following methods. Each of the following shc considered unrelated. (Round all answers to O decimal places.) (a) Straight-line depreciation for 2007. s 8750 (b) Activity method for 2007, assuming that machine usage was 800 hours. (c) Sum-of-the-years'-digits for 2008. s 32084 (d) Double-declining balance for 2008. s 39300