Question

If we have a distribution of x values that is more or less mound-shaped and somewhat symmetric, what is the sample size n needed to claim that the distribution of sample means x from random samples of that size is approximately normal? n ≥

Answer 1

Answer: approximately 30 or more

Explanation:

The sentence 'mound-shaped and somewhat simmetrical' suggests that it follows the central limit theorem (CLT). CLT state that with sufficiently large samples, the sample distribution will be approximately normally distributed. Though there are no specific numbers on sample size, many literatures and mathematicians suggests the '30 or more' value.

However, it is recommended to have as large sample space as possible for more accurate result.