On January 1, 2018, a machine was installed at Dunbar Factory at a cost of $53,000. Its estimated residual value at the end of its estimated life of 4 years is $20,000. The machine is expected to produce 66,000 units with the following production schedule:

2018: 8,000 units

2019: 25,000 units

2020: 18,000 units

2021: 15,000 units

Complete depreciation schedules for

(a) Straight-line,

(b) units-of production,

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