Book value and taxes on sale of assets Troy Industries purchased a new machine $2$ year$($s$)$ ago for $$84,000.$ It is being depreciated under MACRS with a $5-$year recovery period using the schedule $.$ Assume $21\%$ ordinary and capital gains tax rates.

a$.$ What is the book value of the machine?

b$.$ Calculate the firm's tax liability if it sold the machine for each of the following amounts: $$100,800$;$$58,800$;$$40,320$; and $$28,200.$

a$.$ The remaining book value is $$,($Round to the nearest dollar.$)$