A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before treatment, 21 subjects had a mean wake time of 104.0 min. After treatment, the 21...

Extracted text: A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before treatment, 21 subjects had a mean wake time of 104.0 min. After treatment, the 21 subjects had a mean wake time of 78.3 min and a standard deviation of 20.3 min. Assume that the 21 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 104.0 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. O min