Nicole’s getaway spa (ngs) purchased a hydrotherapy tub system to add to the wellness programs at ngs. the machine was purchased at the beginning of the year at a cost of $8,500. the estimated useful life was five years and the residual value was $500. assume that the estimated productive life of the machine is 10,000 hours. expected annual production was year 1, 2,250 hours; year 2, 2,350 hours; year 3, 2,300 hours; year 4, 2,100 hours; and year 5, 1,000 hours.