For a Poisson distribution, find P(2), given λ = 1.

The correct answer is Option (2) → 0.184

For a Poisson distribution,

$P(r) =\frac{λ^re^{-λ}}{r!}$

$P(2)=\frac{1^2.e^{-1}}{2!}=\frac{0.368}{2}$  [$∵e^{-1}=0.368$, from table]

$= 0.184$