A certain machine will cost $50,000 to purchase, will have a six-year life, and $5,000 salvage value. It will be updated in year 4 at a cost of $15,000. Its annual operating cost is expected to be $30,000 per year. At an inflation rate of 5% per year and a real interest rate of 10% per year, the present worth of the machine is closest to? please show work