Hi! I need some help on this stats question regarding a 95% confidence interval for mean wake times for a population with the treatment. Any help would be super appreciated.

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 105.0 min. After treatment, the 21 subjects had a mean wake time of 80.9 min and a standard deviation of 20.5 min. Assume that the 21 sample values appear to be from a normally distributed population and construct a 95% 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 105.0 min before the treatment? Does the drug appear to be effective? Construct the 95% condence interval estimate of the mean wake time for a population with the treatment. mm