If X∼Binomial(n=2,p=0.5)X \sim Binomial(n=2, p=0.5)X∼Binomial(n=2,p=0.5), what is the probability generating function GX(s)G_X(s)GX(s)?
0.25 + 0.5s + 0.25s^2
(0.5 + 0.5s)^2
s^2
0.5 + 0.5s