Computing Depreciation under Alternative methods

At the beginning of the year, Palermo Brothers, Inc., Purchased a new plastic water bottle making machine at a cost of $$100,000.$ The estimated residual value was $$20,000.$ Assume that the estimated useful life was eight years and the estimated productive life of the machine was $220,000$ units. Actual annual production was as follows:

Year $1$ units $40,000$ units

Year $2$ units $50,000$ units

Year $3$ units $60,000$ units

Year $4$ units $70,000$ units

Required:

$1.$ Assuming a half year accounting convention, compute depreciation expense for years $1$ & $2$ under:

a$.$ Straight$-$line $($S$/$L$)$

b$.$ Sum of the years$$ Digits $($SYD$)$

c$.$ Double$-$declining$-$balance $($DDB$)$

d$.$ Units of production $($use two decimal places for the per unit output factor$)$