
where is
called the
binomial coefficient ' N over n', what stands for the number of combinations
when taking n objects out a collection of N objects. Suppose that an event has a probability p to occur. Examples of such events are 'heads or tails', and the chance on a certain number on a dice. The binomial distribution gives the probability of n successes for a number of N events. When p=1/2, we find the binomial:
