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... AT&T 11:29 AM COD41%) Exit Question 2 1 pts Variance is equal to 0 for: (select all that apply) O a constant an expected value O a random variable a discrete random variable a continuous random variable O a random variable plus a constant O a random variable multiplied by a constant

Answer 1

Answer is option A, B)

for a constant, variance is always zero

For expected value,

Let For E(x)

Then var(x) = E( x - E(x))²

Var of E(x)

Var(E(x)) = E( E(x) - E(x))² = 0

So variance is 0 of an expected value

.

A random variable will have zero variance if and only if , it is a constant