Purity Ice Cream Company bought a new ice cream maker at the beginning of the year at a cost of $20,000. The estimated useful life was four years, and the residual value was $2,180. Assume that the estimated productive life of the machine was 9,900 hours. Actual annual usage was 3,960 hours in year 1; 2,970 hours in year 2; 1,980 hours in year 3; and 990 hours in year 4.

Required:
1.	Complete a separate depreciation schedule for each of the alternative methods.(Round your answers to the nearest dollar amount. Omit the "$" sign in your response.)

a.	Straight-line.

Year	Depreciation Expense	Accumulated Depreciation	Net Book Value
At acquisition			$
1	$	$
2
3
4

b.	Units-of-production (use four decimal places for the per unit output factor).

Year	Depreciation Expense	Accumulated Depreciation	Net Book Value
At acquisition			$
1	$	$
2
3
4

c.	Double-declining-balance.

Year	Depreciation Expense	Accumulated Depreciation	Net Book Value
At acquisition			$
1	$	$
2
3
4