Bounding a Random Variable. Suppose that Y is a random variable, and we are interested in whether or not Y 5 c for some constant c. For example, Y could be the random variable P in our clinical trial Example 4,7. I. We might be interested in whether or not P 5 p,,, where pf, is the probability that u patient will be a success without any help from the treatment being studied. Suppose that we have to make one of two available decisions: