Suppose that Y₁, Y2₂,... are i.i.d. RVs with EY₁ = μ and Var (Y₁) = 0² € (0, [infinity]). Set Xk := Yk+Yk+1+Yk+2, k = 1, 2, ..., and put Sn = X₁ + ···+Xn. (a) Compute EXk, Var (Xk) and Cov (X₁, Xk) for j‡ k. Sn-3μn (b) Find lim,→ PS-3un ≤ x), ( < x), x € R. o√3n Hints: (b) Be careful: there is a (small) trap. Note that the X;'s are not independent, but the sum Sn can be represented as a sum of independent RVs. Can you compute Var (Sn)? You can take for granted that if Un - U and V₁ c = const as n → [infinity], then Un + VnU+c (this can be shown using the same techniques as employed when doing tutorial Problem 2 in PS-9).