A swimming school wants to determine whether a recently hired instructor is working out. 42 out of 80 of Instructor A's students passed the lifeguard certification test on the first try. In comparison, 64 out of 80 of more experienced Instructor B's students passed the test on the first try. We are interested in determining whether there is sufficient evidence to conclude that the experienced instructor pass rate is higher than that of the new instructor. The power of this test, if the actual population proportions are 0.6 and 0.8 for Instructor A and Instructor B respectively, is approximately: