Teen smoking, part II. Consider again the Vermont study discussed in Exercise 17.

a) Create a 95% confidence interval for the difference in the proportion of children who may smoke and have approving parents and those who may smoke and have disapproving parents.

b) Interpret your interval in this context.

c) Carefully explain what "95% confidence" means.

Exercise 17

Teen smoking, part I. A Vermont study published in December 2001 by the American Academy of Pediatrics examined parental influence on teenagers' decisions to smoke. A group of students who had never smoked were questioned about their parents' attitudes toward smoking. These students were questioned again two years later to see if they had started smoking. The researchers found that, among the 284 students who indicated that their parents disapproved of kids smoking, 54 had become established smokers. Among the 41 students who initially said their parents were lenient about smoking, 11 became smokers. Do these data provide strong evidence that parental attitude influences teenagers' decisions about smoking?

a) What kind of design did the researchers use?

b) Write appropriate hypotheses.

c) Are the assumptions and conditions necessary for inference satisfied?

d) Test the hypothesis and state your conclusion.

e) Explain in this context what your P-value means.

f) If that conclusion is actually wrong, which type of error did you commit?