Q12. For the joint random variables, X and Y, E(X) = 4, E(Y) = 6, V(X) = 2, V(Y) = 4, Cov(X,Y)=-2. Calculate the value of V(2X - Y): a) 16 b) 20 c) 12 d) 4 e) 36 I

Let W = 2X + 5Y – 3Z, where the random variables X, Y, and Z satisfy E(X)= 2, V(X)= 5, E(Y)= -3, V(Y)=4, E(Z)=7, V(Z) = 6, Cov(X,Y) = -1, Cov(Y, Z) =3, Cov(Z, X)= 2. Calculate E(W), V (W) and Cov(W, Y).

We have the following information about the random variables X and Y: 0.5, дY – 1,o = 1, o = 2.25. Calculate the variance of Z 1X + 7Y, | a) when the coefficient of correlation is p(X, Y) = 0.33: b) when X and Y are independent random variables: