Air-USA has a policy of booking as many as 26 persons on an airplane that can seat only 24. (Past studies have revealed that only 89% of the booked passengers actually arrive for the flight.)

Find the probability that if Air-USA books 26 persons, not enough seats will be available.
prob =

Is this probability low enough so that overbooking is not a real concern for passengers if you define unusual as 5% or less?


What about defining unusual as 10% or less?