A machine costing $211,000 with a four-year life and an estimated $15,000 salvage value is installed in Luther Companys factory on January 1. The factory manager estimates the machine will produce 490,000 units of product during its life. It actually produces the following units: 122,500 in 1st year, 123,000 in 2nd year, 121,400 in 3rd year, 133,100 in 4th year. The total number of units produced by the end of year 4 exceeds the original estimatethis difference was not predicted. (The machine must not be depreciated below its estimated salvage value.)