thank you!!!

A three-year-old machine has a cost of $20,200, an estimated residual value of $1,200, and an estimated useful life of 38,000 machine hours. The company uses units-of-production depreciation and ran the machine 3,300 hours in year 1: 6,850 hours in year 2 and 6700 hours in year 3. Calculate the net book value at the end of the third year Net book value