If x is a random variable then E2x5 A E2x E5x O B E2x O

If x is a random variable, then E(2x+5) = ? ( ) A. E(2x) + E(5x) O B. E(2x) OC. E(5) OD, 2E(x) + 5

Solution

1.

Note that

E(ax + b) = aE(x) + b

Thus,

E(2x + 5) = 2E(x) + 5 [ANSWER, D]

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2.

As

V(ax + b) = a^2 V(x)

Then

V(2x + 5) = 2^2 V(x)

= 4V(x) [ANSWER, A]