The goodness of fit is measured using \( R^2 \), which represents the proportion of variance in the dependent variable explained by the independent variables.

The goodness of fit in regression is measured using the **R-squared (R²)** value. This statistic indicates how well the regression model explains the variability of the dependent variable. In simple terms, R² ranges from 0 to 1: an R² of 0 means the model does not explain any variability in the data, while an R² of 1 means the model perfectly explains the variability. For example, an R² of 0.85 means that 85% of the variation in the dependent variable can be explained by the independent variables in the model, indicating a good fit.