Box-Jenkins(ARIMa) Models Three basic ARIMA models for a stationary time series yt (1)Autoregressive model of order p(ar(p) y1=0+y1+如2y12+…+yn+E1 1. e,, y, depends on its p previous values (2) Moving Average model of order g malg) y 6+8,-61E,1-6,E t-2 t-9 1. e, y, depends on g previous random error terms3 Box-Jenkins (ARIMA) Models  Three basic ARIMA models for a stationary time series yt : (1) Autoregressive model of order p (AR(p)) i.e., yt depends on its p previous values (2) Moving Average model of order q (MA(q)) i.e., yt depends on q previous random error terms, t 1 t 1 2 t 2 p t p t y =  + y + y + + y + − −  − , t t 1 t 1 2 t 2 q t q y = + − − − − − − −         