Airplanes approaching the runway for landing are required to stay in localizer (a certain distance left and right of the runway). When an airplane deviates from localizer, it is sometimes referred to as exceedance. Consider one airline at a medium-sized airport with thirty daily arrivals and an expedience rate of 12%. In an effort to improve the expedience, pilots went through a new training program. You have been hired as a consultant to evaluate the ‘before and after' rates to determine the effectiveness of the training. Just prior to a meeting with the Board of Directors, you have been asked for the probability that on a particular day:
The only resources available to you are your statistics text and a basic solar-powered calculator (e.g., TI-36X), both of which happened to be in your briefcase. Thus, you need to produce a "five-minute back-of-an-envelope" answer.
A. More than ten planes have an expedience.
B.Five planes or fewer experience an expedience.
C. More than two but fewer than five experience an exceedance.