Question: Recent near misses in the air, as well as several fatal accidents, have brought air traffic controllers under close scrutiny. As a result of a high-level inquiry into the accuracy of speed and distance determinations through radar sightings of airplanes, a statistical test was proposed to check the air traffic controllers' claim that a commercial jet's position can be determined, on the average, to within 110 feet in the usual range around airports in the United States. The proposed test was given as H0: µ ≤ 110 versus the alternative H1: µ 1 = 120 feet.