Answer Happy

Required information Angioplasty is a medical procedure in which an obstructed blood vessel is widened. In some cases, a wire mesh tube, called a stent, is placed in the vessel to help it remain open. An article presents the results of a study comparing the effectiveness of a bare metal stent with one that has been coated with a drug designed to prevent re-blocking of the vessel. A total of 5321 patients received bare metal stents, and of these, 841 needed treatment for re-blocking within a year. A total of 1122 received drug coated stents and 134 of them required treatment within a year. Let ex represent the population proportion of patients with bare metal stents who needed treatment and let py represent the population proportion of patients with drug coated stents who needed treatment. Find a 98% confidence interval for the difference PX - Py. Round the answers to four decimal places. The 98% confidence interval is (0.013 0.064