Question 11.97

druguse

14. Illicit Drug Use Among Young People. Monitoring the Future (www.monitoringthefuture.org), at the University of Michigan, is an “an ongoing study of the behaviors, attitudes, and values of American secondary school students, college students, and young adults.” They reported the lifetime prevalence of the use of any illicit drug among 8th-graders, 10th-graders, and 12th-graders, as shown in the table.

8th-graders 10th-graders 12th-graders
Have used an
illicit drug		 3,655 6,527 7,461
Have never used
an illicit drug		 13,345 9,873 7,139
  1. Before you perform the hypothesis test, what result might you expect? Look over the data set carefully to see whether you can detect significant differences between the levels of the variables. Then see whether your hypothesis test bears out your intuition.
  2. Test, using level of significance , for differences among the proportions of children in those grades who have ever used an illicit drug.