a factory machine was purchased for $375 000 on january 1, 2015. it was estimated that it would have a $75,000 salvage value at the end of 5 year useful life. it was also estimated that the machine would be run 40000 hours ination, the 5 years. the company ran the machine for 4000 actual hours in 2015. if the company uses the units-of activity method of depreciation exprense for 2015 would be