E ((Z-Uz)^2) = E(Z^2) - Uz^2 --- Eq1
Uz = cUx
subbing in z = b + cX in Eq1
=E(b^2 + 2cX + (cX)^2) - (cUx)^2
= b^2 + 2c *(E(X)) + c^2(E(X^2)) - c^2 * Ux^2
= b^2 + 2cE(X) + c^2((E(X^2)) - Ux^2)
Why do i get b^2 + 2cE(X) extra???????
E ((Z-Uz)^2) = E(Z^2) - Uz^2 --- Eq1
Uz = cUx
subbing in z = b + cX in Eq1
=E(b^2 + 2cX + (cX)^2) - (cUx)^2
= b^2 + 2c *(E(X)) + c^2(E(X^2)) - c^2 * Ux^2
= b^2 + 2cE(X) + c^2((E(X^2)) - Ux^2)
Why do i get b^2 + 2cE(X) extra???????