Ayayai Airlines purchased an aircraft on January $1,2019,$ at a cost of $$40,800,000.$ The estimated useful life of the aircraft is $20$ years,

with an estimated salvage value of $$4,750,000.$ On January $1,2022$ the airline revises the total estimated useful life to $15$ years with a

revised salvage value of $$3,300,000.$

$($a$)$

Compute the accumulated depreciation and book value at December $31,2021$ using the straight$-$line method and the double$-$

declining$-$balance method.