Although the binomial distribution is discrete and the normal distribution is continuous,the normal distribution is a good approximation for the binomial whenever nP(1 - P) 9 where n = number of trials,and P = the probability of success in any given trial.

Question

Although the binomial distribution is discrete and the normal distribution is continuous,the normal distribution is a good approximation for the binomial whenever nP(1 - P)> 9 where n = number of trials,and P = the probability of success in any given trial.

Quizplus · Accepted Answer

This is a well-known rule of thumb for the approximation of the binomial distribution by the normal distribution. When nP(1 - P) > 9, the distribution of the number of successes in n independent trials with probability of success P is approximately normal, with mean np and standard deviation sqrt{np(1-p)}.

Although the Binomial Distribution Is Discrete and the Normal Distribution