Waterways Tours uses the units$-$of$-$activity method in depreciating its tour boats. One boat was purchased on January $1,2006,$ at a cost of $$148,000.$ Over its four$-$year useful life, the boat is expected to be driven $100,000$ miles. The salvage value is expected to be $$8,000.$Instructions$($a$)$Compute the depreciation cost per unit. $($b$)$Prepare a depreciation schedule assuming actual mileage was: $2008,26,000$: $2009,32,000$:$2010,25,00$; and $2011,17,000.$