Practical calculations for single-entry ANOVA
Analysis of variance and regression. Design of experiments

To speed things up and limit the risk of calculation errors, we fill in the 2 table, known as the analysis of variance table, using the practical formulas in table 3 . These formulas make it easy to calculate "by hand" the moderately complex problems that most engineers face. Above all, they obviate the need to calculate differences of the type $x_{ij}-x_{i•}$ , which have a large number of significant digits, thus avoiding rounding errors and reducing the space used in computer memories.