Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Thomas J. Brock is a CFA and CPA with more ...

Central Limit Theorem: A sampling distribution of the mean is approximately normally distributed if the sample size is sufficiently large. This is true no matter what the population distribution is.

The aim of this paper is to provide an overview of sample size estimations for the most frequent type of group studies that result in continuous, binary and ordered categorical outcomes. In recent ...

In the first part of this piece I pointed out why it can be difficult to validate TAR using control set metrics. When the overall proportion of responsive documents is very low, it becomes ...