According to the Centers for Disease Control and Prevention, in 2008, 6.7% of 12- to 17-year-olds had used marijuana in the previous 6 months. The Drug Abuse and Resistance Education (DARE) program underwent several major changes to keep up with technology and issues facing students in the 21st century. After the changes, a school resource ofﬁcer (SRO) thinks that the proportion of 12- to 17-year-olds who have used marijuana in the past 6 months has decreased.
(a) Determine the null and alternative hypotheses.
(b) If sample data indicate that the null hypothesis should not be rejected, state the conclusion of the SRO.
(c) Suppose, in fact, that the proportion of 12- to 17-year-olds who have used marijuana in the past 6 months is 6.4%. Was a Type I or Type II error committed?