Various depreciation methods—two years On September 6, 2017, East River Tug Co. purchased a new tugboat for $400,000. The estimated life of the boat was 20 years, with an estimated residual value of $40,000. Compute the depreciation on this tugboat in 2017 and 2018 using the following methods. Apply the half-year convention. (If necessary, round to the nearest dollar.)