Depreciation Under Different Methods

On January 1, 2010, Ron Shelley purchased a new tractor to use on his farm. The tractor cost $100,000. Ron also had the dealer install a front-end loader on the tractor. The cost of the front-end loader was $7,000. The shipping charges were $600, and the cost to install the loader was $800. The estimated life of the tractor was eight years, and the estimated service-hour life of the tractor was 12,500 hours. Ron estimated that he could sell the tractor for $15,000 at the end of eight years or 12,500 hours. The tractor was used for 1,725 hours in 2013. A full year's depreciation was taken in 2010, the year of acquisition.

Compute depreciation expense for 2013 under each of the following methods:

1.) Straight-line $ 11675 (got it right!)

2.) Double-declining-balance (When computing annual depreciation, round to the nearest dollar.) $ ----

3.) Sum-of-the-years'-digits (In your calculations, round any division to 5 decimal places and your final answer to the nearest dollar.) $ 12972 (I got this right too!)

4.) Service-hours (In your calculations, round per-hour depreciation rate to the nearest cent and your final answer to the nearest dollar.) $ ----

Thanks for any help at all!