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

105.0

min. After treatment, the

14

subjects had a mean wake time of

98.9

min and a standard deviation of

24.8

min. Assume that the

14

sample values appear to be from a normally distributed population and construct a

95%

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

105.0

min before the treatment? Does the drug appear to be effective?

Construct the

95%

confidence interval estimate of the mean wake time for a population with the treatment.