# Recent content by farbror

1. ### Question about poisson distributed variables

Ok, I'm not really sure if I follow your reasoning there. The beginning is ok, due to the fact that X is a discrete random variable. 2X will only give us even non-negative values; I'm still with you. But in the next step, I'm lost. Why can't 2X be Poisson distributed (2\lambda) when X is...
2. ### Question about poisson distributed variables

Okay, lets see if I can explain my notation... X is my random variable with a poisson distribution I'm trying to verify if the statement X in Po([lamb]) implies that 2X in Po(2[lamb]) I hope this is clear enough /farbror
3. ### Question about poisson distributed variables

Okay, Hurkyl, I can understand your reasoning there. So my idea of the proof is no good. Any other ideas how I should be able to prove/disprove this implication? Thanks! /farbror
4. ### Question about poisson distributed variables

Hi, I'm trying to prove if X~Po(m) => 2X~Po(2m) But I'm not sure how to prove or disprove it. I'm thinking about using the addition formula, but is this the right approach? X_1~Po(m) X_2~Po(n) X_1+X_2~Po(m+n) n=m => X_1=X_2 => 2X_1~Po(2m) Any help is appreciate. Thanks /farbror