Plummer Industries purchased a machine for $40, 800 and is depreciating it with the straight line method over a life of 8 years, using a residual value of $2, 400. At the beginning of the sixth year, an extraordinary repair was made costing $4, 800, the estimated useful life was extended to 13 years, and no change was made to the estimated residual value. Calculate depreciation expense for year 6. (Do not round intermediate calculations.) Depreciation Expense