Ramone Travel offers helicopter service from suburban towns to John F. Kennedy International Airport in New York City. Each of its six helicopters makes between 1,350 and 2,100 round-trips per year. The records indicate that a helicopter that has made 1,350 round-trips in the year incurs an average operating cost of $450 per round-trip, and one that has made 2,100 round-trips in the year incurs an average operating cost of $350 per round-trip. Read the requirements. Requirement 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.