On January 1, 2013, Boston Company purchased a machine having an invoice price of $13,000. Boston paid transportation and installation costs totaling $3,000. During installation the machine was damaged in an accident and repairs cost $500. The machine is estimated to have a 4-year useful life and a $1, 400 residual value. REQUIRED: calculate depreciation expense and book value as of December 31, 2014, assuming double declining-balance method of depreciation