Question

A clinical trial was conducted to test the effectiveness of a drug used for treating insomnia in older subjects. After treatment with the​ drug, 22 subjects had a mean wake time of 93.8 min and a standard deviation of 44.1 min. Assume that the 22 sample values appear to be from a normally distributed population and construct a 95​% confidence interval estimate of the standard deviation of the wake times for a population with the drug treatments. Does the result indicate whether the treatment is​ effective?

Answer 1