If XXX is a discrete random variable with P(X=1)=0.5P(X=1) = 0.5P(X=1)=0.5 and P(X=3)=0.5P(X=3) = 0.5P(X=3)=0.5, what is E[X2]E[X^2]E[X2]?
555
444
222
101010