Recall that Figure14.26 (a) gives n = 16 weekly values of Pages Bookstore sales (y), Pages advertising expenditure (x₁), and competitor’s advertising expenditure (x₂). When we fit the model y = β₀ + β₁x₁ + β₂x₂ + ϵ to the data, we find that the Durbin–Watson statistic is d = 1.63̅. Use the partial Durbin–Watson table on the page margin to test for positive autocorrelation by setting α equal to .05.

Data from Figure 14.26(a)

Transcribed Image Text:

FIGURE 14.26 Pages Bookstore Sales and Advertising Data, and Residual Analysis (a) The data and the MINITAB output of the residuals from a simple linear regression relating Pages sales to Pages advertising expenditure Os BookSales Observation 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Adver 18 20 20 25 28 29 29 28 30 31 34 35 36 38 41 45 Compadv 10 10 15 15 15 20 20 25 35 35 35 30 30 25 20 20 sales 22 27 23 31 45 47 45 42 37 39 45 52 57 62 73 84 Predicted 18.7 23.0 23.0 33.9 40.4 42.6 42.6 40.4 44.7 46.9 53.4 55.6 57.8 62.1 68.6 77.3 Residual 3.3 4.0 -0.0 -2.9 4.6 4.4 2.4 1.6 -7.7 -7.9 -8.4 -3.6 -0.8 -0.1 4.4 6.7 Durbin-Watson = 0.65