8. An important distribution in the multivariate setting is the multivariate normal distribution. Let X be...
The random vector x (XI, X2,... ,Xk)' is said to have a symmetric multivariate normal distribution if x ~ Ne(μ, Σ) where μ 1k, i.e., the mean of each X, is equal to the same constant μ, and Σ is the equicorre- lation dispersion matrix, i.e. when k 3, μ-0, σ2-2 and ρ 1/2, find the probability that Hint: Recall that if x = (Xi, , Xk), has a continuous symmetric dis tribution, then all possible permutations of X1,... ,Xk...
3. Let X ~ N2(u, ) be a bivariate Normal random vector, where 6-61-10 X = = | 12 (a) Find the distribution of Y1 = X1 + X2. (b) Let Y2 = X1 +aX2. Find value a such that Yį and Y2 are independent.
10. Let the random variables X ~ NGIX, σ%) and Y ~ Nuy,ơ be jointly continious normal random variables. Now suppose their joint pdf is X and Y are said to have a bivariate normal distribution (a) Given this joint pdf, show that X and Y are independent. (b) The most general form of the pdf for a bivariate normal distribution is What must be true about k for X and Y to be independent bivariate normal random variables? 10....
Problem 1. (Bivariate Normal Distribution) Let Z1, Z2 be i.i.d. N(0,1) distributed random variables, and p be a constant between –1 and 1. define X1, X2 as: x3 = + VF5223X = v T14:21 - VF52 23 1) Show that, (X1, X2)T follows bivariate Normal distribution, find out the mean vector and the covariance matrix. 2) Write down the moment generating function, and show that when p= 0, X11X2.
Graybill, 1961]. Let x -(X1, X2) have a bivariate normal distribution with pdf where Q-2x-x1x2 + 4 _ 11x1-5T2 + 19, and k is a constant. Find a constant a such that P(3X1-X2 < a) 0.01.
Let X1 and X2 be independent standard normal random vari ables, and let Y-AX-b, where Y-(y, Y)т, X-(X1, X2)T, b (1, -2) and (a) Determine the joint pdf of ı and Y2 by using the formula given in class for the joint pdf of Y = g(X) when X and Y are random vectors of the same dimension, and q is invertible with both g and its inverse differentiable (b) Show that the joint pdf in (a) can be expressed...
Let X = (X1, X2) be a bivariate normal random vector such that Mi = 4,42 = 6,01 = 25, 02 = 16 and p= 0.7. 1. Find P(X2 <5|X1 = 3).
4. Let (X,Y) be a bivariate normal random vector with distribution N(u, 2) where -=[ 5 ], = [11] Here -1 <p<1. (a) What is P(X > Y)? (b) Is there a constant c such that X and X +cY are independent?
3. For n 2 2, let X have n-dimensional normal distribution MN(i, V). For any 1 3 m < n, let X1 denote the vector consisting of the last n - m coordinates of X < n, let 1 (a). Find the mean vector and the variance-covariance matrix of X1. (b). Show that Xi is a (n- m)-dimensional normal random vector.
Let X = (X1, X2) be a 2 x 1 random vector having joint pdf (1 x € (0, 1) ~ [0, 1] 10 otherwise. Find the probability P(X1 < 0.5, X2 < 0.5)