How do you calculate residual standard deviation? - Answers

Residual standard deviation is calculated by first determining the residuals, which are the differences between observed values and predicted values from a regression model. Next, you square these residuals, sum them up, and divide by the number of observations minus the number of parameters estimated (degrees of freedom). Finally, take the square root of this result to obtain the residual standard deviation. This measure indicates the average distance that the observed values fall from the regression line.