need help with C. Double-declining- balance method

Depreciation by three methods; partial years 1,400 hours during Year 1, 2,600 hours in Year 2, 2,300 hours in Year 3, and 1,260 hours in Year 4. Required: balance method. Note: FOR DECLINING BALANCE ONLY, round the final multiplier to four decimal places. Then, round the answer for each year to the nearest whole dollar. a. Straight-line method b. Units-of-activity method c. Double-declining-balance method