Using the formula for the mean lag given in Eq. (17.4.9), verify the mean lag of 10.959 quarters reported in the illustration of  the following table.

Coeff. Coeff. Coeff. It| 3.249 3.783 |t| It| 3.943 3.712 3.511 3.338 3.191 7.870 5.634 0.048 mg 0.054 mg 0.059 4.305 0.069 0.062 0.053 0.039 0.022 0.041 0.034 1.276 1.538 1.903 m16 m17 mi mj0 m18 0.030 0.029 2.171 0.030 0.033 0.065 0.069 0.072 4.694 0.073 0.072 4.202 4.673 4.795 m19 m11 m12 m13 m14 m15 2.235 2.294 2.475 2.798 m20 m4 1.031 m ms Mean lag 10.959 4.468 0.037 0.042 m7 A 0.525 D.W. 2.00 se 1.066