Mountain View Resorts purchased equipment at the beginning of 2021 for $40,000. Residual value at the end of an estimated four-year service life is expected to be $8,000. The machine operated for 2,200 hours in the first year and the company expects the machine to operate for a total of 10,000 hours over its four-year life. Calculate depreciation expense for 2021, using the following depreciation methods: activity-based