Consider the following linear combination: Z = 4X - 5Y with E(X) = 3.2, V(X) = 1.3, E(Y) = 4.6, V(Y) = 5.1, and Cov (X, Y) = 0. What is the correct value of E(Z)? A. -20.3 B. -10.2 C. -6.7 D. 10.2 E. 20.3

Respuesta :

Answer:

Option B.

Step-by-step explanation:

The given values are

E(X) = 3.2, V(X) = 1.3, E(Y) = 4.6, V(Y) = 5.1, and Cov (X, Y) = 0.

The given linear combination is  

[tex]Z=4X-5Y[/tex]

Now,

[tex]E(Z)=E(4X-5Y)[/tex]

It can be written as

[tex]E(Z)=4E(X)-5E(Y)[/tex]

Now, substitute the given values.

[tex]E(Z)=4(3.2)-5(4.6)[/tex]

[tex]E(Z)=12.8-23[/tex]

[tex]E(Z)=-10.2[/tex]

Therefore, the correct option is B.