The hourly operating cost of a plane that seats up to 381 passengers is estimated to be $12,720. If an airline charges each passenger a fare of $240 per hour of flight, find the hourly profit P it earns operating the plane as a function of the number of passengers x. [HINT: The cost function is constant (variable cost = 0).] P(x) = Specify the domain. (Enter your answer using interval notation.) What is the least number of passengers the plane must carry to make a profit? passengers