T&K Rapp Travel offers transportation service from Southern California to Northern California. Each of its 10 buses helicopters makes between 1,000 and 2,000 round-trip per year. The records indicate that a bus helicopter that has made 1,000 round-trips in the year incurs an average operating cost of $4,000 per round-trip, and one that has made 2,000 round-trips in the year incurs an average operating cost of $5,500 per round-trip. Show your calculations please.

a) Using the high-low method, estimate the linear relationship y=a+bX, where y is the total annual operating cost of a bus and X is the number of round-trips it makes to Northern California during the year. Show your calculation

b) If T&K Travel expects each bus to make, on average, 1,500 round-trips in the coming year, what should its estimated operating budget for the helicopter fleet be?