Question

I wanna see how they got that answer. please show all the step or if you know how to do it on the calculator ti-84 .Thank you!

12/5/2019 Math 1342 Practice Final Exam-aleis philips 16. A clinical trial was conducted to test the effectiveness of a drug used for treating insomnia in older subjects. After treatment with the drug, 17 subjects had a mean wake time of 97.9 min and a standard deviation of 42.4 min. Assume that the 17 sample values appear to be from a normally distributed population and construct a 95% confidence interval estimate of the standard deviation of the wake times for a population with the drug treatments. Does the result indicate whether the treatment is effective? Find the confidence interval estimate. 31.58 64.53 min <g< min (Round to two decimal places as needed.) Does the result indicate whether the treatment is effective? O A. Yes, the confidence interval indicates that the treatment is not effective because the interval does not contain 0 minutes. B. Yes, the confidence interval indicates that the treatment is effective because the interval does not contain 97.9 minutes. C. Yes, the confidence interval indicates that the treatment is effective because the interval contains 0 minutes. *D. No, the confidence interval does not indicate whether the treatment is effective. E. Yes, the confidence interval indicates that the treatment is not effective because the interval contains 0 minutes. F. Yes, the confidence interval indicates that the treatment is effective because the interval does not contain 0 minutes. G. Yes, the confidence interval indicates that the treatment is not effective because the interval does not contain 97.9 minutes. YOU ANSWERED nothing w S PDF

Answer 1

The formula to calculate the confidence interval of standard deviation is:

(n-1)32 X²a/2 (n - 1)32 X 1-a/2

X²_0.025 = 6.907

X²_0.975 = 28.845

s = 42.4

Note that this is the confidence interval for the variance. Hence, you should take an underroot to calculate the confidence interval.

n = 17

Lower bound: √(16 * 42.4 * 42.4 / 28.845) = 31.58

Upper bound: √(16 * 42.4 * 42.4 / 6.907) = 64.53

Correct option: D) because we cannot tell from the confidence interval of the standard deviation whether the treatment was effective.