ABSTRACT
Stage 1: find the critical level of the mean IQ that would just have given us a significant result To do this we need to know what z-value would have given us a one-tailed significance level of 0.05. Looking in z-tables in Appendix XIV we find that z is 1.645. The appropriate version of the z-test is:
where Ac (calculated below) is the critical mean for the sample that would give a z of 1.645 and n is the sample size.
