A machine that cost $400,000 has an estimated residual value of $40,000 and an estimated useful life of 20,000 machine hours. The company uses units-of-production depreciation and ran the machine 3,000 hours in year 1, 8,000 hours in year 2, and 6,000 hours in year 3. Required: Calculate its book value at the end of year 3. (Do not round intermediate calculations.)