If you repeat a "yes/no" - experiment times, and the number of successes is (how often "yes" occurs), then follows a binomial probability distribution. A binomial experiment therefore consists of equal and independent experiments, each of which can have exactly two outcomes.
The probability to observe successes is .
In this formula, the chance for "success" is still and .
The variables and are called the parameters of the binomial distribution.
If a statistic is binomially distributed with parameters en then the following is true:
the expected value is:
Your graphing calculator has two programs for quickly calculating binomial probabilities.
For probabilities of the type you should use the binomial probability distribution function.
For probabilities of the type you should use the binomial cumulative distribution function.
Probabilities such as en you should convert to the previous form.