Assignment Task: A doctor released the results of clinical trials for a vaccine to prevent a particular disease. In these clinical? trials, 200,000 children were randomly divided in two groups. The subjects in group 1? (the experimental? group) were given the? vaccine, while the subjects in group 2? (the control? group) were given a placebo. Of the 100,000 children in the experimental? group, 21developed the disease. Of the 100,000 children in the control? group, 43 developed the disease.
Why is such a large number of subjects needed for this? study? Need Assignment Help?
A. The number of subjects is so large because these are clinical? trials, which require a significant number of subjects.
B. The number of subjects is so large because there is a low incidence rate of the disease.
C. The number of subjects is so large because the vaccine is very effective.
D. The number of subjects is so large because the vaccine is not very effective.