Question

A drug company is testing a new drag which is supported to reduce blood pressure. From the nine people who are used as subjects, it is found that the average drop in blood pressure is 2.28 points, with a standard deviation of 0.82 points. What is the 95% confidence interval for the mean change in pressure?

Answer 1

95% of the data falls between 0.64 and 3.92

Explanation:

Using the Empirical Rule, 95% of the data will fall 2 standard deviations above and below the mean. Therefore, from the mean of 2.28, the lower change will be 2.28 - 2(0.82)= 0.64 and the upper change will be 2.28 + 2(0.82)= 3.92‬