Question

If E(X) = 4 and X follows Poisson’s distribution, then V(X) = ______.

Options

• 2

• −2

• 4

• −4

Answer 1

If E(X) = 4 and X follows Poisson’s distribution, then V(X) = 4.

Explanation:

For a Poisson distribution, the mean E(X) and the variance V(X) are equal.
So, if E(X) = 4, then V(X) = 4.