The normal distribution is used to test about a population mean for large samples if the population standard deviation is known. "Large" is usually defined as _______.
A) at least 10
B) at least 5% of the population size
C) at least 30
D) at least 12
E) at least 100

Question

Quizplus · Accepted Answer

A sample size of at least 30 is generally considered "large" enough to assume that the distribution of the sample means will be approximately normal, even if the underlying population distribution is not normal. This is known as the Central Limit Theorem.

The Normal Distribution Is Used to Test About a Population