Mountain View Resorts purchased equipment at the beginning of 2021 for $36,000. Residual value at the end of an estimated four-year service life is expected to be $6,100. The machine operated for 2,700 hours in the first year and the company expects the machine to operate for a total of 11,000 hours over its four-year life. Calculate depreciation expense for 2021, using each of the following depreciation methods: (1) straight-line, (2) double-declining-balance, and (3) activity-based.