anova formula - SERP Analysis

https://www.statsdirect.com/help/analysis_of_variance/one_way.htm

https://www.geeksforgeeks.org/maths/anova-formula/

https://en.wikipedia.org/wiki/Analysis_of_variance

https://online.stat.psu.edu/stat415/lesson/13/13.2

https://www.scribbr.com/statistics/one-way-anova/

https://www.jmp.com/en/statistics-knowledge-portal/one-way-anova

https://byjus.com/anova-formula/

https://www.graphpad.com/guides/the-ultimate-guide-to-anova

https://www.openintro.org/go/%3Fid%3Dstat_better_understand_anova%26referrer%3D/book/os/index.php

https://support.minitab.com/en-us/minitab/help-and-how-to/statistical-modeling/anova/how-to/one-way-anova/methods-and-formulas/analysis-of-variance/