Sheridan Ltd. purchased a new machine on April 4, 2017. at a cost of $172,000. The company estimated that the machine would have a residual value of $16,000. The machine is expected to be used for 10,000 working hours during its four-year life. Actual machine usage was 1,500 hours in 2017; 2,200 hours in 2018; 2,400 hours in 2019; 1,900 hours in 2020; and 2,000 hours in 2021. Sheridan has a December 31 year end. (2) Diminishing-balance using double the straight-line rate for 2017 through to 2021. 2017 expense A 2018 expense $ 2019 expense $ 2020 expense $ 2021 expense $