Aclinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. before treatment, 15 subjects had a mean wake time of 100.0 min. after treatment, the 15 subjects had a mean wake time of 92.6 min and a standard deviation of 43.7 min. assume that the 15 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 100.0 min before the treatment? does the drug appear to be effective?