Question 2 (a) (b) Mr. Ng collected the closing stock quotations for Company ABS for 150 days. He examined the autocorrelation function and partial autocorrelation hunctlon plots, which are shown m Figure 2-1 _ Evaluate the figure and discuss what ARINfA model the stock price is likely to follow? Figure 2-1 : Autocorrelation fitnction and partial autocorrelation Hanction plots for the price of stock -0.2 12 14 16 zo 24 (S marks) Mr. Tan built an ARIMA model to fit the price of Hund XYZ. The parameter estimates he obtained are shown m Table 2-1. Write down the ARINIA model, and predict the hind price for the next period if the current price is 21 _6463_ Table 2-1 : Parameter estimates Parame ter AR 1 Constant Coefficient 0.5486 9.0295 SE 0.0845 0.6082 6_49 14_85 p 0.000 0.000 (12 marks)