3. What correct model
3.1 Yt = Yt-1 + Zt - Zt-1 / 23
a) ARIMA (1,0,1)
b) ARIMA (2,0,2)
c) ARIMA (0,1,1)
d) This is not ARIMA model
3.2 yt = 0.5yt-1 + 0.3yt-2 + Zt - 0.1zt-2 - 0.4zt-2
a) ARIMA (1,0,1)
b) ARIMA (2,0,2)
c) ARIMA (0,1,1)
d) This is not ARIMA model
3.3 yt-1 = 0.5yt-2 + 0.1zt-1 + 0.2zt-2
a) ARIMA (1,0,1)
b) ARIMA (2,0,2)
c) ARIMA (0,1,1)
d) This is not ARIMA model
3.4 yt = 0.2yt-2^2 + zt - 0.1zt-1
a) ARIMA (1,0,1)
b) ARIMA (2,0,2)
c) ARIMA (0,1,1)
d) This is not ARIMA model