A machine costing $270,000 with a four-year life and an estimated $50,000 salvage value is installed in Luther Company's factory on January 1. The factory manager estimates the machine will produce 500,000 units of product during its life. It actually produces the following units: year 1, 128,000; year 2, 130,000; year 3, 126,000; and year 4, 124,500. The total number of units produced by the end of year 4 exceeds the original estimate-this difference was not predicted. (The machine must not be depreciated below its estimated salvage value.)