How do you calculate r2?

Answer 1

R², or the coefficient of determination, is calculated by taking the ratio of the variance explained by the regression model to the total variance in the dependent variable. It is computed as ( R^2 = 1 - \frac{SS_{res}}{SS_{tot}} ), where ( SS_{res} ) is the sum of squares of residuals (the differences between observed and predicted values) and ( SS_{tot} ) is the total sum of squares (the differences between observed values and their mean). A higher R² value indicates a better fit of the model to the data.