Question

What is the Central Limit Theorem used for?

Answer 1

It is the basis for statistical measures and inferences - ASSUMING a "normal distribution".

Explanation:

In practice it means that as you collect a larger sample, the mean of the sample approaches the real mean of the population. This allows us to decide on the amount of sampling we will need to arrive at satisfactory conclusions (also considering our acceptable risk level).

Great lesson:
https://www.khanacademy.org/math/ap-statistics/sampling-distribution-ap/sampling-distribution-mean/v/central-limit-theorem

Additional info:
http://www.dummies.com/education/math/statistics/how-the-central-limit-theorem-is-used-in-statistics/