Let X1,..., Xn be a random sample from a n(, 2) population. (a) Find expressions for 1,...,4,

Let X1,..., Xn be a random sample from a n(μ, σ2) population.
(a) Find expressions for θ1,...,θ4, as defined in Exercise 5.8, in terms of μ and σ2.
(b) Use the results of Exercise 5.8, together with the results of part (a), to calculate Var σ2.
(c) Calculate Var S2 a completely different (and easier) way: Use the fact that (n - 1 )S2/σ2 ~ X2n-I.