- #1
EvenSteven
- 4
- 0
Find [tex]cov(Y,Z)[/tex] where [tex] Y = 2X_1 - 3X_2 + 4X_3[/tex] and [tex]Z = X_1 + 2X_2 - X_3[/tex]
Information given [tex]E(X_1) =4[/tex]
[tex]E(X_2) = 9 [/tex]
[tex]E(X_3) = 5[/tex]
[tex]E(Y) = -7[/tex]
[tex]E(Z) = 26[/tex]
I tried expanding cov(Y,Z) = E(YZ) - E(Y)E(Z) but can't figure out how to calculate E(YZ)
Information given [tex]E(X_1) =4[/tex]
[tex]E(X_2) = 9 [/tex]
[tex]E(X_3) = 5[/tex]
[tex]E(Y) = -7[/tex]
[tex]E(Z) = 26[/tex]
I tried expanding cov(Y,Z) = E(YZ) - E(Y)E(Z) but can't figure out how to calculate E(YZ)