9. (8 points) A study investigated the effect of aspirin on heart disease. A group of patients who were at risk for heart disease were randomly assigned to take either aspirin or a placebo. At the end of the year, the number of patients suffering from heart disease was recorded in the following contingency table. Compute the following Disease No Disease Total Placebo 25 75 100 Aspirin 15 135 150 Total 40 210 250 (a) (4 points) The risk of having heart disease in the placebo group and the risk of having heart disease in the aspirin group. Give your answers are proportions rounded to the nearest thousandth. (Three decimal places.) (b) (2 points) The relative risk of having heart disease in the placebo group compared to the aspirin group. (c) (2 points) The percent increase in risk of having heart disease in the placebo group. 10. (5 points) In an ABC News poll a random sample of n = 1506 adults were asked "Compared to buying things by mail order or in a store, do you think that buying things over the Internet poses more of a threat to your personal privacy, less of a threat, or about the same?" Of the people surveyed, 75% said that this was "More of a threat." (a) (2 points) What is the margin of error for this poll? Give your answer as a percentage rounded to the nearest tenth. (b) (3 points) What is the conservative 95% confidence interval for the population propor- tion that would have responded, "More of a threat"