Problem 2. Consider the following models (1) yt = 0.7yt-1 +0.68+-1 + Et (2) (1 - B)yt =0.7yt-1 - 0.7yt-2 +0.65+-1 + Et (3) (1 - B* )yt = 0.7y+-1 -0.7y+-5 +0.65-1 + Et(b) If we use notation ARIMA(p,d,q) (P,D, Q)m to represent an ARIMA model, what are the values of p, d, q, P, D, Q, m for the three models?(c) Using arima.sim function in R to simulate the three models and plot the simulated series. Make the length of the time series be 100. For model (3), you can modify the code shown here https://robjhyndman.com/hyndsight/simulating-from-a-specified-seasonal-arima-model/ to simulate