Comparing three depreciation methods

Dexter Industries purchased packaging equipment on January $8$ for $$86,400.$ The equipment was expected to have a useful life of $3$ years, or $21,600$ operating hours, and a residual value of $$5,400.$ The equipment was used for $8,640$ hours during Year $1,6,480$ hours in Year $2,$ and $6,480$ hours in Year $3.$

Required:

Determine the amount of depreciation expense for the $3$ years ending December $31,$ by $($a$)$ the straight$-$line method, $($b$)$ the units$-$of$-$activity method, and $($c$)$ the double$-$declining$-$balance method. Also determine the total depreciation expense for the $3$ years by each method. Do not round intermediate calculations when determining the depreciation rate. Round the final answers for each year to the nearest whole dollar.

Depreciation Expense

What method yields the highest depreciation expense for Year $1?$

What method vields the most depreciation over the $3-$year life of the equipment?