A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before​ treatment,
14 subjects had a mean wake time of
100.0 min. After​ treatment, the
14 subjects had a mean wake time of
77.3 min and a standard deviation of
24.4 min. Assume that the
14 sample values appear to be from a normally distributed population and construct a
90​% 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
100.0 min before the​ treatment? Does the drug appear to be​ effective?