## Function Binomial-Cdf

(

**binomial-cdf** < p > < n > < k > )

Suppose an event occurs with probability ` p' per trial. This function<br> computes the probability of `

k' or more events occurring in ` n' trials. Note<br> that this is the complement of the usual definition of cdf. This function<br> approximates the actual computation using the incomplete beta function, but is<br> preferable for large `

n' (greater than a dozen or so) because it avoids

summing many tiny floating-point numbers.

The implementation follows Numerical Recipes in C, section 6.3.