Question - Dietary supplementation in Canadian athletes. Dietary supplements are often used by athletes to enhance performance, training, and recovery. There are, however, potential risks of taking supplements, especially for athletes who are subject to doping control. In Canada, a recent study was performed to evaluate the dietary supplementation practices of high-performance Canadian athletes.3 Surveys were administered to n = 440 athletes associated with the country's eight Canadian Sport Centres.

(a) Overall, 383 athletes reported having taken a dietary supplement within the previous six months. Construct a 95% confidence interval for the proportion of high-performance Canadian athletes who have taken a supplement in the previous six months.

(b) Test the hypothesis that no more than 85% of the Canadian athletes use supplements. State the two hypotheses, the test statistic, and P-value.