A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Beforetreatment, 21 subjects had a mean wake time of 103.0 min. Aftertreatment, the 21 subjects had a mean wake time of 99.7 min and a standard deviation of 22.9 min. Assume that the 21 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 103.0 min before thetreatment? Does the drug appear to beeffective?

Construct the 90% confidence interval estimate of the mean wake time for a population with the treatment.

nothing

min<<

nothing

min

(Round to one decimal place asneeded.)

What does the result suggest about the mean wake time of 103.0 min before thetreatment? Does the drug appear to beeffective?

The confidence interval

does not include

includes

the mean wake time of 103.0 min before thetreatment, so the means before and after the treatment

could be the same.

are different.

This result suggests that the drug treatment

does not have

has

a significant effect.