The population of all sample proportions has an approximately normal distribution if the sample size (n)is sufficiently large.The rule of thumb for ensuring that n is sufficiently large is:
A)np ≥ 5
B)n(1 - p)≥ 5
C)np ≤ 5
D)n(1 - p)≤ 5 and np ≤ 5
E)np ≥ 5 and n(1 - p)≥ 5

Question

Quizplus · Accepted Answer

The rule of thumb for ensuring that n is sufficiently large is that both np ≥ 5 and n(1 - p)≥ 5. This ensures that the sample size is large enough for the sample proportion to have an approximately normal distribution. Choice E satisfies both conditions, making it the best choice.

The Population of All Sample Proportions Has an Approximately Normal