As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever
A) np ≥ 5
B) n1 - p) ≥ 5 and n ≥ 30
C) n ≥ 30 and 1 - p) = 0.5
D) None of these alternatives is correct.

Question

Quizplus · Accepted Answer

This is known as the normal approximation to the binomial distribution. The condition n(p)(1−p)≥10 should also be met for better accuracy. Choice A only considers the value of np, while choice C only considers the value of (1−p). Choice D is incorrect because there is a valid alternative.

As a Rule of Thumb, the Sampling Distribution of the Sample