Depreciation by three methods; partial years Layton Company purchased tool sharpening equipment on October 1 for $22,140. The equipment was expected to have a useful life of 3 years or 4,320 operating hours, and a residual value of $540. The equipment was used for 800 hours during Year 1,1,500 hours in Year 2,1,300 hours in Year 3, and 720 hours in Year 4. Required: Determine the amount of depreciation expense for the years ended December 31, Year 1, Year 2, Year 3, and Year 4 , by (a) the straight-ilne method (b) the units-of-activity method, and (c) the double-declining-balance method. Note: FOR DECLINING BALANCE ONLY, round the multiplier to four decimal places. Then round the answer for each year to the nearest whole dollar. b. Units-of-activity method c. Double-declining-balance method