If X∼Poisson(λ)X \sim \text{Poisson}(\lambda)X∼Poisson(λ) and P(X=1)=0.4P(X=1) = 0.4P(X=1)=0.4, P(X=2)=0.2P(X=2) = 0.2P(X=2)=0.2, what is λ\lambdaλ?
0.50.50.5
1.01.01.0
1.51.51.5
2.02.02.0