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 > 110. The test was to be carried out at the 0.05 level of significance using a random sample of 80 airplane sightings. The statistician designing the test wants to determine the power of this test if the actual average distance at detection is 120 feet. An estimate of the standard deviation is 30 feet. Compute the power at μ1 = 120 feet.