E-Sharp Company purchased tool sharpening equipment on July 1,2006 , for \(\$ 97,200\). The equipment was expected to have a useful life of three years, or 22,800 operating hours, and a residual value of \(\$ 6,000\). The equipment was used for 3,650 hours during \(2006,8,000\) hours in 2007, 7,850 hours in 2008, and 3,300 hours in 2009.

{Instructions}

Determine the amount of depreciation expense for the years ended December 31, 2006, 2007, 2008, and 2009, by

(a) the straight-line method,

(b) the units-of-production method, and

(c) the double-declining-balance method.

objs. 4,5