A clinical psychologist posits that drug use leads to conduct problems. To test this, he examines whether his adolescent inpatient drug users were elevated in terms of conduct disorder (CD). A sample...

1. A clinical psychologist posits that drug use leads to conduct problems. To test this, he examines whether his adolescent inpatient drug users were elevated in terms of conduct disorder (CD). A sample of 25 was evaluated using a standard measure of CD; they had a mean score of 53. The population mean (µ) for the CD scale is 50 with a standard deviation (σ) of 10. Show calculations for the appropriate test.

a. What are the null and alternative hypotheses?

b. Report and interpret an effect size statistic.