Samples of size n = 600 are taken from a telephone survey, and the mean age is taken for each sample. what is the distribution of the sample means?

a. skewed to the left
b. normal (approximately)
c. not enough information provided
d. skewed to the right

The answer in B. For complicated statistics reasons the Central Limit Theorem states that, for sample sizes of above 25 (or 30 depending on the text!), the distribution of sample means is approximately normal regardless of the distribution of the parent distribution