Given a Binomial Distribution with N Trials and Probability P $n p \geq 5$

Multiple Choice

Given a binomial distribution with n trials and probability p of a success on any trial, a conventional rule of thumb is that the normal distribution will provide an adequate approximation of the binomial distribution if:

A) $n p \geq 5$ and $n ( 1 - p ) \geq 5$ .
B) $n p \leq 5$ and $n ( 1 - p ) \leq 5$ .
C) $n p \geq 5$ and $n ( 1 - p ) \leq 5$ .
D) $n p \leq 5$ and $n ( 1 - p ) \geq 5$ .