A clinical trial was conducted to lest the eflectiveness of a drug for treating insomnia in obler subjocts. Before treatment, 20 subjects had a mean wake time of 101.0 min. After treatment, the 20 subjects had a mean wake time of 78.7min and a standard deviation of 23.2min. Assume that the 20 sample values appear to be from a normally distributed population and construct a 90% confidence interval estimate of the mean wake time for a population with drug treatments. What does the resull suggest about the mean wake time of 101.0 min before the treatment? Does the drug appear fo be effective?Construct the 90% confidence interval estimate of the mean wake time for a population with the treatment. \square{\min }<\mu<\square \min (Round to one decimal place as neoded)
Q. A clinical trial was conducted to lest the eflectiveness of a drug for treating insomnia in obler subjocts. Before treatment, 20 subjects had a mean wake time of 101.0 min. After treatment, the 20 subjects had a mean wake time of 78.7min and a standard deviation of 23.2min. Assume that the 20 sample values appear to be from a normally distributed population and construct a 90% confidence interval estimate of the mean wake time for a population with drug treatments. What does the resull suggest about the mean wake time of 101.0 min before the treatment? Does the drug appear fo be effective?Construct the 90% confidence interval estimate of the mean wake time for a population with the treatment.□min<μ<□min(Round to one decimal place as neoded)
Identify Given Information: Identify the given information.We have a sample size n of 20 subjects, a sample mean xˉ of 78.7 minutes, and a sample standard deviation s of 23.2 minutes. We want to construct a 90% confidence interval for the population mean wake time μ after treatment.
Determine Distribution: Determine the appropriate distribution to use.Since the sample size is less than 30 and we do not know the population standard deviation, we use the t-distribution to construct the confidence interval.
Find T-Value: Find the t-value that corresponds to a 90% confidence level for a t-distribution with n−1 degrees of freedom.For a 90% confidence interval and 19 degrees of freedom (n−1=20−1), we look up the t-value in a t-distribution table or use a calculator with inverse t-distribution functionality. The t-value for a two-tailed test at 90% confidence is approximately 1.729.
Calculate SEM: Calculate the standard error of the mean (SEM).SEM=nsSEM=2023.2SEM≈4.47223.2SEM≈5.188
Calculate ME: Calculate the margin of error (ME).ME=t-value×SEMME=1.729×5.188ME≈8.968
Construct Confidence Interval: Construct the confidence interval.Lower limit = xˉ−MELower limit = 78.7−8.968Lower limit ≈69.7 (rounded to one decimal place)Upper limit = xˉ+MEUpper limit = 78.7+8.968Upper limit ≈87.7 (rounded to one decimal place)
Interpret Results: Interpret the results.The 90\% confidence interval estimate for the mean wake time after treatment is between 69.7 minutes and 87.7 minutes. Since the interval does not include the mean wake time of 101.0 minutes before treatment, this suggests that the drug treatment has effectively reduced the mean wake time.
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