Now the goal of this video is to think about, well what is the expected value of a geometric random variable like this? And I'll tell you the answer in future videos when we will apply this formula. But in this video we're actually going to prove it to ourselves mathematically. But the expected value of a geometric random variable is gonna be one over the probability of success on any given trial. So now let's prove it to ourselves. So the expected value of any random variable is just going to be the probability weighted outcomes that you could have. So you could say it is the probability, the probability that our random variable is equal to one times one plus the probability that our random variable is equal to two times two plus, and you get the general idea, it goes on and on and on.