Let X1 and X2 be any two random variables, then E( Cov( X1, X2) ) =
A. |
X1 times X2, i.e., X1*X2. |
|
B. |
X1 / X2. |
|
C. |
Cov( X1, X2). |
|
D. |
none of the above |
The answer is:
Proof:
Let me know in the comments if anything is not clear. I will reply ASAP! Please do upvote if satisfied!
Let X1 and X2 be any two random variables, then E( Cov( X1, X2) ) =...
QUESTION 15 Let X be a nonnegative random variable (the possible values of X are all nonnegative numbers), and suppose E( X ) = 1, then, the probability that X takes a value greater than 5, cannot be A. larger than 0.1. B. larger than 0.2. C. less than 0.2. D. none of the above. QUESTION 16 Let X be any random variable, and E( X ) = 2, then, the probability that X takes a value greater than 10, cannot...
Let X1 and X2 be two independent standard normal random variables. Define two new random variables as follows: Y-Xi X2 and Y2- XiBX2. You are not given the constant B but it is known that Cov(Yi, Y2)-0. Find (a) the density of Y (b) Cov(X2, Y2)
5. Let X1 and X2 be two independent standard normal random variables. Define two new random variables as follows: Yı = X1 + X2 and ½ = X1 + ßX2. You are not given the constant β but it is known that Cov(Yi,Y) = 0. Find (a) the density of Y2 (b) Cov(Xy½),
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...
6. Suppose random variables X1, X2, X3 have the following properties: E(X1) = 1; E(X2) = 2; E(X3) = −1 V(X1) = 1; V(X2) = 3; V(X3) = 5 COV (X1,X2) = 7; COV (X1,X3) = −4; COV (X2,X3) = 2 Let U = X1 −2X2 + X3 and W = 3X1 + X2. (a) Find V(U) (b) Find COV (U,W).
Let X1 and X2 be random variables, not necessarily independent. Show that E [X1 + X2] = E [X1] + E [X2]. You may assume that X1 and X2 are discrete with a joint probability mass function for this problem, while the above inequality is true also for continuous random variables.
how to calculate cov(x1,x2), cov(x2,x3),cov(x3,x1)?
and how to calculate var(x1),var(x2),var(x3)?
Given three random variables Xi, X2, and X such that X[Xi X2 X 20 -1 E [X] ,1-10 | and var(X)=Σ-| 0 3 0. 1 0.5 1 compuite: 2
Let X1 and X2 be two random variables. Define G as G = E [max (X1, X2)] + E [min (X1, X2)] . Express G in terms of E[X1] and E[X2].
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...
Let X1 and X2 be independent random variables with means μ1 and μ2, and variances σ21 and σ22, respectively. Find the correlation of X1 and X1 + X2. Note that: The covariance of random variables X; Y is dened by Cov(X; Y ) = E[(X - E(X))(Y - E(Y ))]. The correlation of X; Y is dened by Corr(X; Y ) =Cov(X; Y ) / √ Var(X)Var(Y )