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