Sketches Inc. purchased a machine on January 1, 2016. The cost of the machine was $32,000. Its estimated residual value was $10,000 at the end of an estimated 5-year life. The company expects to produce a total of 20,000 units. The company produced 1, 200 units in 2016 and 1, 650 units in 2017. Required: a. Calculate depreciation expense for 2016 and 2017 using the straight-line method. b. Calculate the depreciation expense for 2016 and 2017 using the units-of-production method. (Do not round your intermediate calculations. Round your final answers to the nearest whole dollar.) c. Calculate depreciation expense for 2016 through 2020 using the double-declining balance method. (Round your final answer to nearest dollar value.)