A new medication has been developed to treat the common cold. This new medication was compared with a Vitamin C treatment and a placebo treatment in a clinical trial. Three hundred subjects who had colds were available for the study. The subjects were randomly allocated to the three treatments with 100 in each treatment group. At the end of the treatment period, each subject gave his/her opinion of the effectiveness of the treatment he/she received.
There are three treatments described in the above clinical trial. Why shouldn’t we just perform 3 two-sampleztests ofproportions?
ANSWER OPTIONS:a. Because most of the tests are not significant.b. Because the overall power for all the tests combined is too high.c. Because the sample sizes must be larger for the results to be valid.d. Because the overall a is inflated when performing multiple tests.
I don’t understand why any of these options would be correct. Any help would be appreciated!