We ask whether attending a private school leads to higher or lower performance on a test of social skills. A sample of 100 students from a private school produces a mean of 71.30 on the test, and the national mean for students from public schools is 75.62 (σX = 28.0).
(a) Should we use a one-tailed or a two-tailed test? Why?
(b) What are H0 and Ha?
(c) Compute zobt.
(d) With a = .05, what is zcrit?
(e) What should we conclude about this relationship?