We know the binomial distribution. The binomial distribution tells us that the expected value of a random variable is equal to the number of trials that that random variable is kind of composed of. Before in the previous videos we were counting the number of heads in a coin toss. So this would be the number of coin tosses times the probability of success over each toss. This is what we did with the binomial distribution. So maybe we can model our traffic situation something similar. This is the number of cars that pass in an hour.