5. Here is an example in a vein similar to that of Example 1.2, and originally presented by Berger and Berry (1988). Consider a clinical trial established to study the effectiveness of vitamin C in treating the common cold. After grouping subjects into pairs based on baseline variables such as gender, age, and health status, we randomly assign one member of each pair to receive vitamin C, with the other receiving a placebo.

We then count how many pairs had vitamin C giving superior relief after 48 hours. We wish to test H0 : P(vitamin C better) = 1 2 versus Ha : P(vitamin C better) = 1 2 .