Hi! I need some help on this confidence interval estimate of the mean wake time in this statistics problem. Thank you very much!

A clinical 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 102.0 min. After treatment, the 15 subjects had a mean wake time of 74.1 min and a standard deviation of 23.8 min. Assume that the 15 sample values appear to be from a normally distributed population and construct a 99% condence interval estimate of the mean wake time for a population with drug treatments. What does the result suggest about the mean wake time of 102.0 min before the treatment? Does the drug appear to be effective? Construct the 99% condence interval estimate of the mean wake time for a population with the treatment. :l min