$7-6.$ The "Big$-$Deal" Company has purchased new furniture for their offices at a retail price of $$125,000.$ An additional $$20,000$ has been charged for insurance, shipping, and handling. The company expects to use the furniture for $10$ years $($useful life $=10$ years$)$ and then sell it at a salvage $($market$)$ value of $$15,000.$ Use the SL method of depreciation to answer these questions. $(7\mathrm{.}3)$

a$.$ Use the straight$-$line method to calculate depreciation in year three.

b$.$ Use the $200\%$ declining balance method to calculate the cumulative depreciation through year four.

c$.$ Use the MACRS method to calculate the cumulative depreciation through year five.

d$.$ What is the book value of the GPS receiver at the end of year four when straight$-$line depreciation is used?