Speedy Parcel Service operates a fleet of delivery trucks in a large metropolitan area. A careful study by the company's cost analyst has determined that if a truck is driven 117,000 miles during a year, the average operating cost is 12.8 cents per mile. If a truck is driven only 78,000 miles during a year, the average operating cost increases to 14.9 cents per mile.
Using the high-low method, estimate the variable and fixed cost elements of the annual cost of truck operation and Express the variable and fixed costs in the form Y = a + bX