A three-year-old machine has a cost of $32.600, an estimated residual value of $1,600, and an estimated useful life of 31,000 machine hours. The company uses units-of-production depreciation and ran the machine 4100 hours in year 1: 7,850 hours in year 2. and 6,900 hours in year 3. Calculate the net book value at the end of the third year, Netbook value