round-trips in the year incurs an average operating cost of $300 per round-trip, and one that has made 2,000 round-trips in the year incurs an average operating cost of $250 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.

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?