i want expalanation of units of produce specially year 2024 as soon as possible answer

On January 2, 2021, Archer Company, a skateboard manufacturer, installed a computerized machine in its factory at a cost of $172,400. The machine's useful life was estimated at four years or a total of 180,000 units with a $32,000 trade-in value. Archer Company's yearend is December 31. Calculate depreciation for each year of the machine's estimated useful life under each of the following methods: (Do not round intermediate calculations.) a. Straight-line b. Double-declining-balance c. Units-of-production, assuming actual units produced were