Question: A survey of 200 ninth-graders found that 31.5% had used cigarettes in the past week, and a survey of 250 high-school seniors found that 35.2% had used cigarettes in the past week. Is there significant difference between the two corresponding population proportions?
(a) State the hypotheses.
(b) Using a 5% significance level, determine the rejection and non-rejection regions.
(c) Calculate the test statistic, and interpret the result.
(d) Calculate the p-value, and interpret the result.
(e) Construct a 95% confidence interval for the difference between the two proportions, and answer the original research question.