Answer:
C. The population must be normally distributed.
Explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For us to apply the central limit theorem with a sample size of 14, the underlying population must be normally distributed.
So the correct answer is:
C. The population must be normally distributed.