Transformation of Variables problem (Poisson dist)

**Zenter** · August 6th 2009, 10:29 AM

X is dist. Poisson with mean A, where A is moderately large.

You are given that Y = $X^2$

What is the mean of Y in terms of A?

I know this should be really simple, and I could do it is X was continuous, but how would I approach this, given that X is discrete? I'm sure I'm missing something really obvious here :/

E(Y) = E( $X^2$ ) = ...?

**CaptainBlack** · August 6th 2009, 11:06 AM

Originally Posted by Zenter

X is dist. Poisson with mean A, where A is moderately large.

You are given that Y = $X^2$

What is the mean of Y in terms of A?

I know this should be really simple, and I could do it is X was continuous, but how would I approach this, given that X is discrete? I'm sure I'm missing something really obvious here :/

E(Y) = E( $X^2$ ) = ...?