I ended the previous Uncertainty Wednesday post asking whether an expected value always exists. Going back to the definition, the expected value is the “probability weighted average of a random variable.” So let’s construct an example of a random variable which does not have an expected value. We will consider a probability distribution with infinitely many discrete outcomes, in which the first outcome has probability ½, the second ¼, the third 1/8 and so on. This is a valid probability distr...
