Chi-square distribution introduction

First the global mean is calculated from a matrix of three sets each containing three observations. Then the sum of squares is calculated. Lastly, the concept of degree of freedom is explained.

The sum of squares and degree of freedom calculation from the previous videos are put into a ratio to calculate the F Value, on whose basis the null hypothesis is confirmed or rejected. If variance is higher between samples than within the null hypothesis is more likely to be rejected. The results of a numerical example are interpreted more abstractly and then tested with regards to a confidence interval and the corresponding F table.

The chi-square distribution is used to test a hypothesis. Therefore, expected values are related to observed values using a chi-square distribution. Then using p-value tables the hypothesis is tested at a 5% significance level.