3. Let X be the height of Zebras, assume the X is a random variable with...
Let X be a random variable with mean μ and variance σ2, and let Y be a random variable with mean θ and variance τ2, and assume X and Y are independent. (a) Determine an expression for Corr(X Y , Y − X ). (b) Under what conditions on the means and variances of X and Y will Corr(XY, Y −X) be positive (i.e., > 0 )?
Page 13 of 13 15. (3 points each) Let X be a random variable with a mean of 10 and a variance of 4. Let Y be a random variable with a mean of 8 and a variance of 3. The covariance of X and Y is Oy 0.2. Let W-6Y-4X + 2 a. Find E(W) b. Find Var(W)
(4pt) The variance of random variable X is 4 and the variance of random variable Y is 16. The correlation coefficient between the two random variables X and Y is 0.9. (a) (1pt) Find the covariance between X and Y. (b) A new random variable Z is given by Z = 5x + 1. Find the covariance between X and Z. (1pt) Find the covariance between Y and Z. (2pt)
explain as much as possible! thanks! (4pt) The variance of random variable x is 1 and the variance of random variable Y is 16. The correlation coefficient between the two random variables X and Y is 0.9. (a) (1pt) Find the covariance between X and Y. (b) A new random variable Z is given by Z = 5x + 1. Find the covariance between X and Z. (1 pt) Find the covariance between Y and Z. (2pt)
7. X is a random variable with a mean of 2 and a variance of 3, and Y is a random variable with a mean of 4 and a variance of 5, and the covariance between X and Y is -3. Define (a) Find the expected value of W. b) Find the variance of W
4. [-14 Points] DETAILS (4pt) The variance of random variable X is 1 and the variance of random variable Y is 4. The correlation coefficient between the two random variables X and Y is 0.2. (a) (1pt) Find the covariance between X and Y. (b) A new random variable Z is given by Z = 2X + 1. Find the covariance between X and Z. (1pt) Find the covariance between Y and Z. (2pt)
O. Let X1 and X2 be two random variables, and let Y = (X1 + X2)2. Suppose that E[Y ] = 25 and that the variance of X1 and X2 are 9 and 16, respectively. O. Let Xi and X2 be two random variables, and let Y = (X1 X2)2. Suppose that and that the variance of X1 and X2 are 9 and 16, respectively E[Y] = 25 (63) Suppose that both X\ and X2 have mean zero. Then the...
Thank you Assume that Y is a 3 × 1 random vector with mean vector ,y = μ and covariance matrix ΣΥΥ-σ2 . I. Assume that e is an independent random variable variable with zero mean and variance ф2 . Derive the mean and variance for W-2 1 Y + 5. Derive the covariance matrix between W and Y 6. Derive the correlation matrix between Wand Y. 7. Derive the variance covariance matrix for V- W Y, i.e., derive
Let X ~ N(0, 1) and let Y be a random variable such that E[Y|X=x] = ax +b and Var[Y|X =x] = 1 a) compute E[Y] b) compute Var[Y] c) Find E[XY]
Use this result without proof: if X and Y are two normal random variables with means ux and My respectively, and variances oź and oſ respectively, and Z = X+Y, Z is also a normal random variable with mean (ux + Hy) and variance (ox +og). a) Suppose Yı, Y2, Yz, Y4 and Y5 are all independent normal random variables, each with a mean of 1 and a variance of 5. What is the probability that (Y1 + 2Y2 +...