An experiment with two mutually exclusive and exhaustive outcomes (heads/tails, 
success/failure, etc.) is performed a certain number of times, say n. The experimental trials are 
independent. The probability of success on each trial is a fixed value p (hence the probability of 
failure is a fixed value q = 1 - p). What is the probability that k of the trials are successes? The 
answer is given by binomial probabilities. Change p, below, to another value between 0 and 1 
and observe the changing probabilities. You can also change the NumberOfTrials as well as the 
values of k. Scroll down to see the probability histogram.