*Employing the artificial data generated in Exercise 18.3, use Equation 18.3 (on page 539) to compute the average squared error (ASE) of the local-linear regression estimator for various spans between s ¼ 0:05 and s ¼ 0:95, drawing a graph of ASEðsÞ versus s. What span produces the smallest ASE? Does this confirm your visual selection of the span of the local-linear estimator in Exercise 18.3?