# Math Help - poisson distribution

1. ## poisson distribution

Let X have a Poisson distribution with parameter λ. Show that P[X is even] = (1+e^2λ)/2

2. Originally Posted by jayantamath
Let X have a Poisson distribution with parameter λ. Show that P[X is even] = (1+e^2λ)/2
Substitute x = 2n into the pmf and sum over n (you will need to recognise a standard power series).

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