According to the Kelley Blue Book, a Ford Mustang two$-$door convertible that is worth $$14,776$ today will be worth $$10,600$ in two years $($if it is in excellent condition with average mileage$).$

$($a$)$ Assuming linear depreciation, Construct the depreciation function for this car.

$($b$)$ What will the car be worth in $4$ years?

$($c$)$ At what rate is the car depreciating?