Gafford Company recently paid \(\$ 180,000\) for equipment that will last four years and have a salvage value of \(\$ 30,000\). By using the machine in its operations for four years, the company expects to earn \(\$ 60,000\) annually, after deducting all expenses except depreciation. Present a schedule showing income before depreciation, depreciation expense, and net income for each year and the total amounts for the four-year period assuming

(a) straight-line depreciation,

(b) sum-of-the-years'digits depreciation, and

(c) declining-balance depreciation at twice the straight-line rate.