Suppose that X, Y, and Z are jointly distributed random variables, that is, they are defined on the same sample space. Suppose that we also have the following.
E(X)=5
E(Y)=-3
E(Z)=-7
Var(X)=49
Var(Y)=32
Var(Z)= 47
Compute the values of the expressions below.
E(-2Z-4)=
E((5z-3X)/4))=
Var(5Y+2)=
E(-5Z^2)=
I tried to substitute 1.E(-2Z-4)= -2(-7)-4=10
2.E((5z-3X)/4))= (5(-7)-3(5))/4= -12.5
3.Var(5Y+2)=5(32)+2=16.2
4.E(-5Z^2)=-5(-7)^2=-245
Is this correct?
Please Help!