If it is too long, one answer to either one will be great.
Especially Q10.
9....
9. Show that the process Z 0.7Z,-1+A -0.1A-1 is both invertible and stationary. Express the process Z s (i) a pure MA and (ii a pure AR process 10. The first 200 terms of a time series gave the following results acf rk-0.80 0.67 -0.52 0.390.31 pacf k0.80 0.085 0.112 0.046 0.061 The mean of the observed series was ž 0.03, and s2 3.34. Suggest an appropriate model to the series, justifying your choice