As a general rule,the normal distribution is used to approximate the sampling distribution of the sample proportion only if:
A)the sample size n is greater than 30.
B)the population proportion p is close to 0.50.
C)the underlying population is normal.
D)np and n(1 − p)are both greater than or equal to 5.

Question

Quizplus · Accepted Answer

The best choice(s) is D because it is the essential condition for using a normal approximation for the sampling distribution of the sample proportion. When np and n(1-p) both greater than or equal to 5, the sampling distribution of the sample proportion can be approximated using a normal distribution, regardless of the sample size or the population proportion.

As a General Rule,the Normal Distribution Is Used to Approximate