10-23 Estimating a cost function, high-low method. Reisen Travel offers helicopter service from suburban towns to John F. Kennedy International Airport in New York City. Each of its 10 helicopters makes between 1,000 and 2,000 round-trips per year. The records indicate that a helicopter that has made 1,000 round-trips in the year incurs an average operating cost of $350 per round-trip, and one that has made 2,000 round-trips in the year incurs an average operating cost of $300 per round-trip. 1. Using the high-low method, estimate the linear relationship y= a + bx, where yis the total annual oper- ating cost of a helicopter and Xis the number of round-trips it makes to JFK airport during the year. 2. Give examples of costs that would be included in a and in b. 3. If Reisen Travel expects each helicopter to make, on average, 1,200 round-trips in the coming year, what should its estimated operating budget for the helicopter fleet be?