Depreciation by Three Methods; Partial Years

$1,900$ hours in Year $2,1,600$ hours in Year $3,$ and $900$ hours in Year $4.$

Required:

all final values for each depreciation method and each year to the nearest whole dollar.

a$.$ Straight$-$line method

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

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