## Knowledge Base for Power and Sample Size .com Calculators

There are 4 Articles here.

### Power and Sample Size in a Nutshell

Introductory

A simplified, brief overview that introduces power and sample size calculations.

### Useful Properties of the Normal Distribution

Properties, Normal, z-test

If you're not a statistician it might come as a surprise to learn that many power and sample size formulas can easily be derived using only a minimal amount of basic algebra and knowing just a few useful properties of the Normal distribution.

### Brief Introduction to Z-Tests

Introductory, Normal, z-test

Z-tests are among the most basic of statistical hypothesis testing methods, and are often taught at an introductory level. Nevertheless, they still hold an important position in the realm of applied statistical analysis. They offer, at the very least, a good starting point for many power analysis and sample size determination situations. In this article we go over some z-test basics that will help set up other articles dealing with z-test formula derivations.