Concept:In regression, the sum of residuals (errors) equals zero when the model includes an intercept.Explanation:For a regression equation fitted by the method of least squares, the sum of the deviations of the observed values from the predicted values is always zero.Mathematically, ∑(Yi​−Y^i​)=0.Therefore, the total error is zero, though individual errors can be positive or negative.Thus, the correct answer is "Zero".Answer:Zero