ANS

1

i don't understand how (0,1,1)(0,1,1)12

18. Use the Box-Jenkins methodology to model and forecast the monthly gasoline demand of Yukong Oil Company shown in Table P-17 in Chapter 5. TABLE P-17 Month 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 36. 0 39.0 42.2 44.3 46.6 January February March April May June July August September October November December 46.1 15.5 17.8 18.1 20.5 21.3 19.8 20.5 22.3 22.9 21.1 22.0 22.8 20.4 20.8 22.2 24.1 25.5 25.9 26.1 27.5 25.8 29.8 27.4 29.7 26. 9 29.4 29.9 32.4 33.3 34.5 34.8 39.1 39.0 36.5 37.5 39.7 52.1 53. 1 56.5 58.4 61.7 61.0 65.5 71.0 68.1 67.5 68.8 68. 1 64.4 6 8.1 68.5 72.3 74.1 77.6 79.9 86.7 84.4 81.4 85.1 81.7 82.3 83.6 85.5 91.0 92.1 95.8 98.3 102.2 101.5 98.5 101.1 102.5 102.7 102.2 104. 7 108.9 112.2 109.7 113.5 120.4 124.6 116.7 120.6 124.9 122.2 121.4 125.6 129.7 133.6 137.5 143.0 149.0 149.9 139.5 147.7 154.7 145.8 144.4 1452 148.6 153.7 157. 9 169.7 184.2 163.2 155.4 168,9 178.3 170.0 176.3 174.2 176.1 185.3 182.7 197.0 216.1 1922 48.5 52.6 52.2 50.8 51.9 55. 1 Construct the model by using Box-Jenkins methodology and forecast the monthly gasoline demand of "Yukong Oil Company. Take natural log of demand before modeling for the given data. The seasonally difference followed by a regular difference is, W, = Y, Y,, -Y,-12 +Y,-13 Thus, the ARIMA (0,1,1)(0,1,1), model should be appropriate