A discrete random variable XXX has PMF P(X=2k)=k6P(X = 2k) = \frac{k}{6}P(X=2k)=6k for k=1,2,3k = 1, 2, 3k=1,2,3. What is E[X]E[X]E[X]?
3.53.53.5
146\frac{14}{6}614
4.54.54.5
555