Duluth Ranch, Inc. purchased a machine on January 1, 2018. The cost of the machine was $24,500. Its estimated residual value was $7,500 at the end of an estimated 5-year life. The company expects to produce a total of 10,000 units. The company produced 950 units in 2018 and 1,400 units in 2019. Required: a. Calculate depreciation expense for 2018 and 2019 using the straight-line method. b. Calculate the depreciation expense for 2018 and 2019 using the units-of-production method. c. Calculate depreciation expense for 2018 through 2022 using the double-declining balance method