# Statistics Time series model problem

$$X_t = 2X_{t−1} − 1.7X_{t−2} + 0.7X_{t−3} + w_t − 0.1w_{t−1}$$

Find the characteristic equations, ARIMA order, and $$E[X_t]$$

Also for $$E [\nabla X_t]$$ and determine if $$\nabla X_t$$ is stationary and invertible.

Thanks