Computing Confidence.
1: A health care professional wants to determine the systolic blood pressure of individuals with hypertension who take Atenolol. Thirty such individuals have an average systolic blood pressure of 105, with a sample standard deviation of 23. Find the 95% confidence interval for mean systolic blood pressure for hypertensive individuals who take Atenolol.
2: In a study of the effectiveness of a certain anxiolytic on individuals experiencing panic attacks, out of a 120-person sample, 85 reported a decrease in panic attack frequency. Find the 95% confidence interval for the proportion of patients who experienced a reduction in panic attacks while on the anxiolytic.
3: The following is a list of hospital stay durations, in days, of 16 new mothers after cesarean deliveries:
3, 4, 7, 3, 2, 3, 2, 1, 5, 4, 4, 8, 1, 3, 4, 6
Using this sample data, find the 98% confidence interval for the mean duration of post-cesarean hospital stay.
4: A camp director is interested in the mean number of letters each child sends during his or her camp session. The population standard deviation is known to be 2.5. A survey of 20 campers is taken. The mean from the sample is 7.9. Find the 99% confidence interval for the mean number of letters.