Consider the time series Xt = 4t + Wt + 0.9Wt−1, where Wt ∼ N(0, σ2...

Consider the time series Xt = 4t + Wt + 0.9Wt−1, where Wt ∼ N(0, σ2 ).

(i)What are the mean function and the variance function of this time series? Is this time series stationary? Justify your answer

(ii). Consider the first differences of the time series above, that is, consider Yt = Xt − Xt−1. What are the mean function and autocovariance function of this time series? Is this time series stationary? Justify your answer

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orchestra answered 1 year ago

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