Plummer Industries purchased a machine for $37,200 and is depreciating it with the straight-line method over a life of 8 years, using a residual value of $2,000. At the beginning of the sixth year, an extraordinary repair was made costing $8,000, 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.)