A psychologist in a public school system is asked by the superintendent to provide evidence to the school board that the students will profit from more intensive training. There are 4000 students in the city school system and 794 in this particular high school. The psychologist decides to test the hypothesis that the mean IQ of the students is 110. He has very good reason to believe, from the standardization of the test used, that whatever the mean IQ value is, the variance of IQ scores for these students is 116. Furthermore, in con¬

sultation with the superintendent, the psychologist decides that the prob¬

ability of Type I error should be .05. Since the only definite course of action to be taken is to recommend special training if there is evidence that the mean IQ is greater than 110, and no particular action will be taken if the mean IQ is less than or equal to 110, the psychlogist decides to do a one-tailed test.