Let X1,X2 and X3 be three discrete random variables with P[X1 = 0] = P[X1 = 1] = P[X2 = 0] = P[X2 = 1] = 1 2 and P[X3 = 0] = 1. (i) Characterize all possible coupling between X1 and X2. (ii) Which coupling maximizes the correlation? Which coupling minimiz

Question

Question

Let X1,X2 and X3 be three discrete random variables with

P[X1 = 0] = P[X1 = 1] = P[X2 = 0] = P[X2 = 1] = 1/2

and P[X3 = 0] = 1.

(i) Characterize all possible coupling between X1 and X2.

(ii) Which coupling maximizes the correlation? Which coupling minimizes the

correlation? Do you have an intuitive explanation why these couplings are the

ones that minimize/maximize the correlation?

(iii) Which coupling makes the two random variables uncorrelated?

(iv) Do the tasks (i) − (iii) but for X1 and X3

Answer 1

Similar Homework Help Questions

Let X1, X2, X3 be independent Binomial(3,p) random variables. Define Y1 = X1 + X3 and Y2 = X2 + X3. Define Z1 = 1 if Y1...

Let X1, X2, X3 be independent Binomial(3,p) random variables. Define Y1 = X1 + X3 and Y2 = X2 + X3. Define Z1 = 1 if Y1 = 0; and 0 otherwise. Define Z2 = 1 if Y2 = 0; and 0 otherwise. As Z1 and Z3 both contain X3, are Z1 and Z3 independent? What is the marginal PMF of Z1 and Z2 and joint PMF of (Z1, Z2) and what is the correlation coefficient between Z1 and Z2?
Let X1, X2, X3, . be a sequence of i.i.d. Uniform(0,1) random variables. Define the sequence...

Let X1, X2, X3, . be a sequence of i.i.d. Uniform(0,1) random variables. Define the sequence Yn as Ymin(X1, X2,,Xn) Prove the following convergence results independently (i.e, do not conclude the weaker convergence modes from the stronger ones). d Yn 0. a. P b.Y 0. L 0, for all r 1 Yn C. a.s d. Y 0. Let X1, X2, X3, . be a sequence of i.i.d. Uniform(0,1) random variables. Define the sequence Yn as Ymin(X1, X2,,Xn) Prove the following...
Let X1, X2, X3 be independent random variables with E(X1) = 1, E(X2) = 2 and...

Let X1, X2, X3 be independent random variables with E(X1) = 1, E(X2) = 2 and E(X3) = 3. Let Y = 3X1 − 2X2 + X3. Find E(Y ), Var(Y ) in the following examples. X1, X2, X3 are Poisson. [Recall that the variance of Poisson(λ) is λ.] X1, X2, X3 are normal, with respective variances σ12 = 1, σ2 = 3, σ32 = 5. Find P(0 ≤ Y ≤ 5). [Recall that any linear combination of independent normal...

3. (25 pts.) Let X1, X2, X3 be independent random variables such that Xi~ Poisson (A), i 1,2,3. Let N = X1 + X2+X3. (a)...

3. (25 pts.) Let X1, X2, X3 be independent random variables such that Xi~ Poisson (A), i 1,2,3. Let N = X1 + X2+X3. (a) What is the distribution of N? (b) Find the conditional distribution of (X1, X2, X3) | N. (c) Now let N, X1, X2, X3, be random variables such that N~ Poisson(A), (X1, X2, X3) | N Trinomial(N; pi,p2.ps) where pi+p2+p3 = 1. Find the unconditional distribution of (X1, X2, X3). 3. (25 pts.) Let X1,...
Let X1, X2, and X3 be a random sample from a discrete distribution with probability function...

Let X1, X2, and X3 be a random sample from a discrete distribution with probability function g(x) =x/10 for x= 1, 2, 3, 4 and g(x) = 0 otherwise. What is P(X1< X2< X3)?
3. Suppose that X1, X2, X3 be i.i.d. random variables with P(Xi 0) 2/5 and P(X 1) 3/5. Find the M...

3. Suppose that X1, X2, X3 be i.i.d. random variables with P(Xi 0) 2/5 and P(X 1) 3/5. Find the MGFof X, + X2 + X 3. 3. Suppose that X1, X2, X3 be i.i.d. random variables with P(Xi 0) 2/5 and P(X 1) 3/5. Find the MGFof X, + X2 + X 3.

Let X1, X2, X3 … be independent random variable with P(Xi = 1) = p =...

Let X1, X2, X3 … be independent random variable with P(Xi = 1) = p = 1-P(Xi=0), i ≥ 1. Define: N1 = min {n: X1+…+ Xn =5}, N2 = 3 if X1 = 0, 5 if X1 = 1. N3 = 3 if X4 = 0, 2 if X4 = 1. Which of the Ni are stopping times for the sequence X1, …?
2. Let X1, X2, X3 ..., X, be iid b(1, p) random variables. Let Sn =...

2. Let X1, X2, X3 ..., X, be iid b(1, p) random variables. Let Sn = 27-1Xthen prove that Sn-E(Sn) N(0,1) as n +00. (Sn)
Q2 Suppose X1, X2, X3 are independent Bernoulli random variables with p = 0.5. Let Y;...

Q2 Suppose X1, X2, X3 are independent Bernoulli random variables with p = 0.5. Let Y; be the partial sums, i.e., Y1 = X1, Y2 = X1 + X2, Y3 = X1 + X2 + X3. 1. What is the distubution for each Yį, i = 1, 2, 3? 2. What is the expected value for Y1 + Y2 +Yz? 3. Are Yį and Y2 independent? Explain it by computing their joint P.M.F. 4. What is the variance of Y1...

5. Suppose that X1, X2, and X3 are independent random variables such that E[Xl i =...

5. Suppose that X1, X2, and X3 are independent random variables such that E[Xl i = 12,3. Find the value of E(X 2x1-X3)2]. mt random variables such that EX-0 and ER-i for 0 and ELX 1 for