The Binomial Formula Explained Each piece of the formula carries specific information and completes part of the job of computing the probability of x successes in n independ only-2-event success or failure trials where p is the probability of success on a trial and q is the probability of failure on the trial. The probability of failure q is equal to 1 p. N X.
N X.
N X. X the number of successes it can take the values 0 1 2 3. The full binomial probability formula with the binomial coefficient is P X n. Let us start with an exponent of 0 and build upwards.