Tutoring statistics, rules of usage are key. The tutor shares one about when the normal approximation to the binomial distribution can be used.

The binomial distribution imagines a series of n trials, each with probability p of success and q=(1-p) of failure. The number of successes in n trials is the random variable x.

Apparently, the binomial random variable x can be approximated to normal if np≥5 and also nq≥5.

HTH:)

Source:

PennState Eberly College of Science

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.