A clinical trial was conducted to test the effectiveness of

Last updated: 7/13/2022

A clinical trial was conducted to test the effectiveness of a drug used for treating insomnia in older subjects. After treatment with the drug, 28 subjects had a mean wake time of 90.2 min and a standard deviation of 42.1 min. Assume that the 28 sample values appear to be from a normally distributed population and construct a 90% 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? Find the confidence interval estimate. min<o<min (Round to two decimal places as needed.)