You own a site development company and are considering the purchase of a new grader. Since this is your main business, the grader will be used almost every working day. Given the following parameters, calculate the total hourly cost of ownership + operation (not including operator wages) in $ per operating hour. Purchase price: Fuel, oil, grease, minor repairs: New tires Total estimated life: Major repair/overhaul interval Internal rate of return Salvage value at end of life $350,000 $45.87 / hour $7,500/set, replaced at years 2.5 and 5 12,000 hours $15,000 every 4,000 hours but not at 12,000 hours 8.5% 18% of purchase price Will be in use 70% of working hours, 5 days per week, 10 hours per day, 50 weeks/yr