## Chi-square Test for Independence

Key concepts for understanding the Test for Independence.

## Chi-square Tests Overview

Chi-square tests are very useful in understanding relationships and proportions. This is a concise overview.

## Chi-square Test for Homogeneity

Key concepts of the Chi-square Test for Homogeneity – how it differs from the Test for Indpendence.

## Chi-square Goodness of Fit Test

Key concepts in understanding the Chi-square Goodness of Fit test.

## Why is a two-tail p-value twice the one-tail value?

The logic behind why a two-tail p-value is always twice the one-tail value.

## Tail of the Test?

How to determine which side of the distribution to use in your hypothesis test.

## What is p-value?

Understanding p-value is often a challenge for stats students. Here is a focused explanation.

## 2-Sample z-test

Excerpt for 2-sample z-test coming

## Measurement Scales

This is a studentâ€™s question about the NOIR acronym for the most common measurement scales. Here is my answer:

## Z or T?

Picking the right distribution to use for your hypothesis test is important. For comparing means, we use either the z or the t-distribution. Here’s how to choose the right one.