A clinical trial was conducted to test the effectiveness of a drug for treating
ID: 3375224 • Letter: A
Question
A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before treatment, 20 subjects had a mean wake time of 100.0 min. After treatment, the 20 subjects had a mean wake time of 77.4 min and a standard deviation of 24.8. 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 result suggest about the mean wake time of 100.0 min before the treatment? Does the drug appear to be effective?
Construct the 90% confidence interval estimate of the mean wake time for a population with the treatment.
Explanation / Answer
Confidence Interval 90% confidence
Standard error of the mean = SEM = S/?N = 5.545
t(?, N-1) = 1.729
Confidence interval = m +/- (t(?, N-1)*SEM)
Mean = 77.4
Lower bound: 67.81
Upper bound: 86.99
The result suggests that treatment was effective as the mean wake time decreased from 100. As the Confidence interval does not contain the value of 100