ProbabilityRolling Dice

In this animation you can roll many “virtual” dice at once and see how the results compare to the predicted probabilities:

Notice how, as we roll more and more dice, the observed frequencies become closer and closer to the frequencies we predicted using probability theory. This principle applies to all probability experiments and is called the law of large numbers.

Similarly, as we increase the number of dice rolled at once, you can also see that the probabilities change from a straight line (one die) to a triangle (two dice) and then to a “bell-shaped” curve. This is known as the central limit theorem, and the bell-shaped curve is called the normal distribution.