Mountain View Resorts purchased equipment at the beginning of 2021 for $30.000 Residual value at the end of an estimated four- year service life is expected to be $7,700. The machine operated for 2,600 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 each of the following depreciation methods: (1) straight-line. (2) double declining- balance, and (3) activity-based. (Round your intermediate calculations to 2 decimal places.) Depreciation Expense Straight-line Double declining balance Activity-based