Depreciation by Three Methods; Company purchased equipment on October 1 for $35,860. The equipment was expected to have a useful life of three years, or 4,900 operating hours, and a residual value of $1,560. The equipment was used for 900 hours during Year 1, 1,700 hours in Year 2, 1,500 hours in Year 3, and 800 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-line method, (b) the units-of-activity method, and (c) the double-declining-balance method. Note: Round all final values for each depreciation method and each year to the nearest whole dollar.