A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Beforetreatment, 21 subjects had a mean wake time of 103.0 min. Aftertreatment, the 21 subjects had a mean wake time of 93.3 min and a standard deviation of 21.9 min. Assume that the 21 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 103.0 min before thetreatment? Does the drug appear to beeffective?

Construct the 99% confidence interval estimate of the mean wake time for a population with the treatment.

min<< min

(Round to one decimal place asneeded.)

Use this information to draw an appropriate conclusion about the effectiveness of the drug.