=+11. A beverage company specializing in sales of champagne reports four years of quarterly sales as follows (in millions of $):

Quarter Sales ($M)

1 12 2 41 3 15 4 48 5 25 6 55 7 23 8 69 9 51 10 80 11 54 12 87 13 64 14 94 15 62 16 108 The regression equation is Predicted Sales = 14.15 + 4.87 Quarter.

a) Find the residuals.

b) Plot the residuals against Quarter. Comment.

c) Compute the Durbin-Watson statistic.

d) At a = 0.05, what are the values of dL and dU?

e) Is there evidence of positive autocorrelation? Explain.

f) Is there evidence of negative autocorrelation? Explain.