In: Statistics and Probability
Suppose X1, X2, . . . are a sequence of iid uniform random variables with probability density function f(x) = 1 for 0 < x < 1, or 0, otherwise.
Let Y be a continuous random variable with probability density function g(y) = 3y2 for 0 < y < 1, or 0, otherwise.
We further assume that Y and X1, X2, . . . are independent. Let T = min{n ≥ 1 : Xn < Y }. That is, T is the first time to get a smaller value than Y in the sequence {Xn} ∞n=1(from n=1 to infinity).
(a) Find P(T = 2) = P(X1 ≥ Y, X2< Y ).
(b) Find E(T).
(c) Find Var(T)