TIME SERIES

the seasonal model: Yt = (1 - OB - 0B + 0OBs+ )EtYe = BE t-S t- + 90 6 z-s - 1 2 + 9" + 92 = ( 1+ 02) ( 1+6Question 5 For the model (1 - QBS ) Wt = (1 -01B - 0sBS - OstlBS+)at where s > 3 and at is white noise, find the variance of the process