2. Consider the AR(2) process X_t = 1.1X_{t-1} - 0.18X_{t-2} + Z_t , where {Z_t} is a series of white noise with mean 0 and variance 1, (a) Please show that this series is stationary. (b) Please derive its autocovariance functions. (c) Please derive the first two partial autocorrelation functions.
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Check for stationarity: For an AR(2) process to be stationary, the roots of the characteristic equation must lie outside the unit circle. The characteristic equation for the given process is: 1 - 1.1B - 0.18B^2 = 0 where B is the backshift operator. The roots Show moreā¦
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