How do you determine the variance of a Poisson distribution?
1 Answer
Nov 8, 2015
The Poisson Distribution is that of a discrete random variable. Hence we use the summation procedure.
Explanation:
For any random variable X, the variance is defined as
σ2 = E(X2 ) -[E(X)]2 .
if the random variable is a discrete random variable, we obtain
σ2 =∞∑0 x2 p(x) -[∞∑0x.p(x)]2 where
p(x) =(e−μμxx!) x = 0,1,2,3,-----∞
Finally, the answer is obtained asμ .