I need help with this particular question.

3. The following table shows the sample ACE and PACE of the series= 399 i}=(l-B)Xr. r:L....399.with 23:0 andf1.{'11)=3.25. rl a) Specift'}r a suitable ARLI'IA mode] for {2}} . giving estimates of all parameters. Explain your choice of model. h)Given that X395=llo= 5:395:11153: 51539511132= xg=1ms=and X399=1133= use your model to find the best mean square estimates of Kw and If 451 and estimate the mean squared errors of your predictors. Lag 1 2 3 4 5 6 1' 3 9 111 ACE .3113 .654 .533 .413 .293 .2111 .115 .1131 .1111? -.11111 PA CF .3113 .11116 .1123 -.11153 .11311 .11113 .1133 .1145 .1191 .11113 Lag 11 12 13 14 15 115 11 13 19 211 ACE .1131 .1169 .1196 .111 .12I5 .115 .116 .1115 -.1115 -.1133 PAGE -.11151 -.1191 .1134 .11111 .1134 .1151 .1131 .11115 .11113 .11111