Researchers want to test the effectiveness of a new antianxi

Researchers want to test the effectiveness of a new anti-anxiety medication. Three hundred eighty patients were recruited to participate in the clinical trial. In clinical testing, 50 out of 180 people taking the medication reported symptoms of anxiety. Of the other 200 people receiving a placebo, 70 reported symptoms of anxiety. Combining the two samples together, what is the overall proportion of those who reported symptoms of anxiety among all participants?

0.22

0.32

0.42

0.52

Solution

No of persons in sample 1 (new) = 180

No of persons suffered from anxiety (new) = 50

No of persons in sample 2 (placebo) = 200

No of persons suffered from anxiety (placebo) = 70

Overall proportion of those who reported symptoms of anxiety among all participants = (50 + 70) / (180 +200) = 0.3157 ~ 0.32. (Option B )