Wildhorse Ltd. purchased a new machine on April 4, 2017, at a cost of $180,000. The company estimated that the machine would have a residual value of $18,000. The machine is expected to be used for 10,000 working hours during its four-year life. Actual machine usage was 1,600 hours in 2017; 1,900 hours in 2018; 2,500 hours in 2019; 1,900 hours in 2020; and 2,100 hours in 2021. Wildhorse has a December 31 year end. (a) Calculate depreciation for the machine under each of the following methods: (Round expense per unit to 2 decimal places, e.g. 2.75 and final answers to 0 decimal places, e.g. 5,275.) (1) Straight-line for 2017 through to 2021. 2017 expense $ 67500 2018 expense $ 2019 expense $ 2020 expense $ 2021 expense $ (2) Diminishing-balance using double the straight-line rate for 2017 through to 2021. 2017 expense $ $ 2018 expense $ 2019 expense $ $ 2020 expense $ $ 2021 expense $ (3) Units-of-production for 2017 through to 2021. 2017 expense $ 16,250 2018 expense $ 23,750 2019 expense $ $ 31,250 2020 expense $ 23,750 2021 expense $ 26,250