On January 1, 2020, Walker Inc. acquired equipment for $210,000. The expected useful life is 10 years and the residual value is $3,200. Total service hours for the equipment are estimated to be 30,000 while actual hours for 2020 were 3,600. Compute depreciation expense in 2020, under the following method. Round your answer to the nearest whole dollar. a. Straight-line