amachine cost $45000 to purchase, fuel and minor maintenance are estimated to cost $12.34 per operating hoour (those hours when the engine is operating and machine is doing work). a set of tires cost $3'200 to reace, and their estimated life is 2,800 hr use the machine is expected to last for 8,400hr , after which it will sold at a price equal to 10% if original purchase price. a final set of new tires will not be purchased before the sale. how much should the owner of the machine charge per hour of use, if it is expected that the machine will operate 1,400hr per year? the company's cost of capital rate is 7%.