Question

A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before​ treatment, 17 subjects had a mean wake time of 105.0 min. After​ treatment, the 17 subjects had a mean wake time of 95.6 min and a standard deviation of 23.9 min. Assume that the 17 sample values appear to be from a normally distributed population and construct a 99​% confidence interval estimate of the mean wake time for a population with drug treatments. What does the result suggest about the mean wake time of 105.0 min before the​ treatment? Does the drug appear to be​ effective? Construct the 99​% confidence interval estimate of the mean wake time for a population with the treatment. nothing minless thanmuless than nothing min

Answer 1

After the​ treatment:

Given the sample size and sample mean , sample standard deviation .

The two sided confidence interval for mean based on the sample data is

The 99% confidence interval is

Since 105.0 lies in the confidence interval (), we vare 99% confident that the mean wake time with drug treatment is not different from 105.0. The drug does not appear to be​ effective.