please help with c!! ive trued to figure it out dozens of ways and just canr seem to get it

Depreciation by Three Methods; Partial Years Perdue Company purchased equipment on April 1 for $72,360. The equipment was expected to have a useful life of three years, or 7,020 operating hours, and a residual value of $2,160. The equipment was used for 1,300 hours during Year 1,2,500 hours in Year 2,2,100 hours in Year 3, and 1,120 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) units-of-activity method, and (c) the double-decining-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 doliar b. Units-of-activity method c. Double-declining-balance method