The binomial test|
is used for the study of rare events.
It calculates the exact probability of
finding 'x' or more failures (or white
or male or large or tail) as opposed
to n-x or less successes (or black or
female or small or heads) after having
done 'n' experiments, 'n' observations
or studying a sample of size 'n'. This
particular procedure also gives a double
sided binomial probability.