Crane Ltd$.$ purchased a new machine on April $4,2017,$ at a cost of $$172,000.$ The company estimated that the machine would have a residual value of $$16,000.$ The machine is expected to be used for $10,000$ working hours during its four$-$year life. Actual machine usage was $1,500$ hours in $2017$; $2,200$ hours in $2018$; $2,400$ hours in $2019$; $2,100$ hours in $2020$; and $1,800$ hours in $2021.$ Crane has a December $31$ year end.

$($a$)$