The value of estimated autocorrelation parameter ρˆ is 0.4166. On fitting the regression equation to the variables (Y 0.4166Y t t 1 − − ) and (X 0.4166X it i,(t 1) − − ) for i = 1,2,3,4, we have a D value of 1.769. The value of dU for n = 60 and p-1 = 4 is 1.56 at the 1% level. The fitted equation on the original variables is as follows: