Q3. Suppose {Zt} is a time series of independent and identically distributed random variables such that Zt ~ N(0, 1). the N(0, 1) is normal distribution with mean 0 and variance 1. Remind: In your introductory probability, if Z ~ N(0, 1), so Z2 ~ x2(v = 1). Besides, if U ~ x2(v), so E[U] = v and Var(U) = 2v. We define a process by setting: Zit, if t even Xt = (Z21 -1)/V2, ift is odd (a) Illustrate that {Xi} ~ WN(0, 1). (b) This time series are not necessarily independent. ***Commentaire:**The purpose of this exercise is to demonstrate that there are white noise processes where the variables of this series are not independent