Here we will walk through the five-step hypothesis testing procedure for comparing the proportions from two independent groups. In order to use the normal approximation method there must be at least 10 "successes" and at least 10 "failures" in each group. In other words, \(n p \geq 10\) and \(n (1-p) \geq 10\) for both groups.
If this assumption is not met you should use Fisher's exact method in Minitab or bootstrapping methods in StatKey.