Depreciation by three methods; partial years

Layton Company purchased tool sharpening equipment on October $1$ for $$38,880.$ The equipment was expected to have a useful life of $3$ years or $7,560$ operating hours, and a residual value of $$1,080.$ The equipment

was used for $1,400$ hours during Year $1,2,600$ hours in Year $2,2,300$ hours in Year $3,$ and $1,260$ hours in Year $4.$

Required:

Determine the amount of depreciation expense for the years ended December $31,$ Year $1,$ Year $2,$ Year $3,$ and Year $4,$ by $($a$)$ the straight$-$line method, $($b$)$ the units$-$of$-$activity method, and $($c$)$ the double$-$declining$-$

balance method.

Note: FOR DECLINING BALANCE ONLY, round the multiplier to four decimal places. Then round the answer for each year to the nearest whole dollar.

a$.$ Straight$-$line method

b$.$ Units$-$of$-$activity method

c$.$ Double$-$declining$-$balance method