A researcher drew a sample of 400 people, measured their IQs, and tested the null hypothesis that µIQ = 100. The researcher obtained z 3.00, which led her to reject the hypothesis ( was 15.0).
(a) What was the standard error of the mean?
(b) What was the mean of the sample?
(c) The test yielded a statistically significant outcome. Does it appear to be an important one? Explain. (d) How much of a standard deviation did the discrepancy between X and hyp amount to?