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.

answer

see attachment

explanation

the given function is

this function has y-intercept at

-4 and a slope of 2.

note that, the graph has a positive slope.

the graph that represents this function is the straight line that moves upward from left to right.

the graph touches the y-axis at -4.

the correct choice is the graph shown in the attachment.

7/2

(decimal: 3.5)

welcome ; )

step-by-step explanation: