I will attach my question.

Problem 3 (30 points) Suppose that Y = BX+U X =y Z+V. where Y, X, Z, B, y. U, and I' are scalars, Z is independent of U and V , E(U) = E(V)=0, and E(U') = 07, E(1)=}, E(UV)=OUT , E(X])=My , E(Z')=My