Let X∼Poisson(λ)X \sim \text{Poisson}(\lambda)X∼Poisson(λ). What is E[X2]E[X^2]E[X2]?
λ\lambdaλ
λ2\lambda^2λ2
λ2+λ\lambda^2 + \lambdaλ2+λ
λ2+2λ\lambda^2 + 2\lambdaλ2+2λ