Randy Automotive purchased equipment on October 1, 2021, at a total cost of $ 150,000. The machine has an estimated useful life of 8 years or 100,000 hours, and an estimated residual value of $ 10,000. During 2021 and 2022, the machinery was used 4,400 and 12,800 hours, respectively. Instructions Compute depreciation expense at December 31, 2021 and December 31, 2022, under the following depreciation methods: 2021 2022 Straight-line depreciation Units-of-production depreciation Double diminishing-balance depreciation