Rabuet Travel offers helicopter service from suburban towns to John F. Kennedy International Airport in New York City. Each of its eleven helicopters makes between 1,000 and 2,500 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 $700 per round-trip, and one that has made 2,500 round-trips in the year incurs an average operating cost of $550 per round-trip. 1. Using the high-low method, estimate the linear relationship y=a+bX, where y is the total annual operating cost of a helicopter and X is the number of round-trips it makes to JFK airport during the year