Question

12. A pharmaceutical company claims that side effects will be experienced by fewer than 20% of the patients who use medication X. A clinical trial with a random sample of 400 patients was conducted in which half of the patients were randomly assigned to take medication X and the other half received a placebo. Of those that received medication X they find 68 who experienced side effects.
Assuming all conditions for inference were met, which of the following is a 90 percent confidence interval for the proportion of patients that will experience side effects while taking medication X?

(A) (0.1391, 0.2009)
(B) (0.2744, 0.4057)
(C) (0.2849, 0.3951)
(D) (0.6257, 0.7343)
(E) (0.6416, 0.7184)

Answer 1

Answer:

(0.2849, 0.3951)

Explanation: