A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before treatment, 22 subjects had a mean wake time of 105.0 min. After treatment, the 22 subjects had a mean wake time of 95.7 min and a standard deviation of 22.2 min. Assume that the 22 sample values appear to be from a normally distributed population and construct a 99% 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 105.0 min before the treatment? Does the drug appear to be effective?

Step-by-step explanation:

We want to determine a 99% confidence interval estimate of the mean wake time for a population with drug treatments.

Number of sample, n = 22

Mean, u = 95.7 min

Standard deviation, s = 22.2 min

For a confidence level of 90%, the corresponding z value is 2.58.

We will apply the formula

Confidence interval

= mean ± z × standard deviation/√n

It becomes

95.7 ± 2.58 × 22.2/√22

= 95.7 ± 12.21

The lower end of the confidence interval is 95.7 - 12.21 = 83.49 min

The upper end of the confidence interval is 95.7 + 12.21 = 107.91 min

The result suggests that there is no significant difference between the mean wake time before and after treatment. Therefore, the drug does not appear to be effective.

the answer would be 484

step-by-step explanation:

just multiply 0.484 times 1,000 (formula)