Current attention has focused upon the health care system, particularly upon managed care plans. A study was undertaken in one managed care plan to determine whether patients' reports of satisfaction with plan were related to their leaving the plan in 1 year. In the random sample of 120 patients who reported that they were satisfied with plan, 30 left that plan within 1 year. In the second random sample of 150 patients who reported that they were not satisfied with plan, 62 left in 1 year. Calculate a 95% confidence interval for the difference in the proportions of patients who left the plan within 1 year relative to their satisfaction reports.