From Elsmar Cove Quality Assurance and Business Standards Wiki
A random variable has a binomial distribution (with parameters n and p) if it is the number of "successes" in a fixed number n of independent random trials, all of which have the same probability p of resulting in "success." Under these assumptions, the probability of k successes (and n-k failures) is nck pk(1-p)n-k, where nck is the number of combinations of n objects taken k at a time: nck = n!/(K!(N-k)!). The expected value of a random variable with the binomial distribution is n_p, and the standard error of a random variable with the binomial distribution is (n_p_(1 ] - p))_.
See also
SPC Monitoring and Statistical Analysis Techniques Discussion Threads
Bimodal Distribution
References
