Comparing three depreciation methods Dexter Industries purchased packaging equipment on January 8 for $72,000. The equipment was expected to have a useful life of three years, or 18,000 operating hours, and a residual value of $4,500. The equipment was used for 7,600 hours during Year 1, 6,000 hours in Year 2, and 4,400 hours in Year 3. Required: 1. Determine the amount of depreciation expense for the three years ending December 31, by (a) the straight-line method, (b) the units-of-activity method, and (c) the double-declining-balance method. Also determine the total depreciation expense for the three years by each method. Round the final answers for each year to the nearest whole dollar.