1. The problem statement, all variables and given/known data Let's say I flip a coin 80 times. I keep track of what happens when I flip it twice. What is the probability that I will find that, on the average, x heads happen per trial? 2. Relevant equations 3. The attempt at a solution Determine what values x can hold in each trial in order to obtain a mean of X. Then I can use the binomial distribution on those values. Add the probabilities up. That gives me my probability.