Question

(A5). A random variable X has Poisson distribution with mean equal to 0.4. What is the probability that the random variable is greater than zero?

Answer 1

$\lambda =0.4\\ P(X>0)=1-P(X=0)\\ =1-\frac{e^{-0.4}(0.4)^{0}}{0!}=1-0.0.67=0.33$