A clinical trial was conducted to test the effectiveness of a drug used for treating insomnia in older subjects. After treatment with theâ drug, 20 subjects had a mean wake time of 90.7 min and a standard deviation of 43.7 min. Assume that the 20 sample values appear to be from a normally distributed population and construct a 98â% confidence interval estimate of the standard deviation of the wake times for a population with the drug treatments. Find the confidence interval estimate.

Arecent study focused on the number of times men and women who live alone buy take-out dinner in a month. assume that the distributions follow the normal probability distribution and the population standard deviations are equal. the information is summarized below. statistic men women sample mean 24.85 21.33 sample standard deviation 5.54 4.93 sample size 34 36 at the 0.01 significance level, is there a difference in the mean number of times men and women order take-out dinners in a month? state the decision rule for 0.01 significance level: h0: μmen= μwomen h1: μmen ≠ μwomen. (negative amounts should be indicated by a minus sign. round your answers to 3 decimal places.) compute the value of the test statistic. (round your answer to 3 decimal places.) what is your decision regarding the null hypothesis? what is the p-value? (round your answer to 3 decimal places.)