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, 30 subjects had a mean wake time of 93.8min and a standard deviation of 43.3 min. Assume that the 30 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?

Answer 1

Solution:-

90​% confidence interval estimate of the standard deviation of the wake times for a population with the drug treatments is 35.7439 < σ < 55.4112.

=> Yes, the confidence interval indicates that the treatment is not effective because the interval does not contain 0 minutes.