Georgia 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 used 4,400 and 12,800 hours, respectively.

Compute depreciation expense at December 31, 2021 and December 31, 2022 (for both years), under each of the following depreciation methods: (1) Straight-line depreciation, (2) Units-of-Production depreciation, and (3) Double Diminishing-balance depreciation. Show how your calculations are derived.