Qusetion: Make a 95% confidence interval for the mean of the cholesterol-level population using each of the samples gathered in Exercise, assuming that you know that σ = 45.3 mg/100mL (three confidence intervals, one for each sample).

Exercise: The time taken for cessation of bleeding was recorded for a large number of persons whose fingers had been pricked. The mean time was found to be 1.407 min and the standard deviation was .588 min. In an effort to determine whether pressure applied to the upper arm increases bleeding time, six persons had pressure equal to 20 mmHg applied to their upper arms and had their fingers pricked. For these six persons, the times taken for bleeding to stop were 1.15, 1.75, 1.32, 1.28, 1.39, and 2.50min. Give a 95% confidence interval for the mean bleeding time under pressure for the six persons and draw some conclusion as to whether pressure increases bleeding time.