For Y=aX+bY = aX + bY=aX+b, which variance formula is correct?
Var(Y)=aVar(X)+bVar(Y) = aVar(X) + bVar(Y)=aVar(X)+b
Var(Y)=a2Var(X)Var(Y) = a^2Var(X)Var(Y)=a2Var(X)
Var(Y)=(a+b)Var(X)Var(Y) = (a+b)Var(X)Var(Y)=(a+b)Var(X)
Var(Y)=a2Var(X)+b2Var(Y) = a^2Var(X) + b^2Var(Y)=a2Var(X)+b2