There are n people eligible to vote in a certain election. Voting requires registration. Decisions are made independently. Each of the n people will register with probability p 1 . Given that a person registers, he or she will vote with probability p 2 . Given that a person votes, he or she will vote for for the 1st candidate with probability p 3 . Let X denote the number of votes for the 1st candidate. (a) What is the probability mass function of X ? Please make sure to specify what values X takes. (b) Find E[X]. (c) Find SD(X)