Probability, Events and Random Variables

Suppose today you want to make a guess about the S&P500’s quote at the end of tomorrow. What is the chance to observe a value 35,501? Indeed, today we don’t know if 35,501 will be the true value tomorrow, thus we are faced something real called uncertainty. The word ‘uncertainty’ Uncertainty is a synonymous for random experimentRandom experiment, an empirical phenomenon or a given procedure whose outcome cannot be predicted with certainty. This can be interpreted as lack of information. A random experiment can be observed, but it hasn’t deterministic regularity at all. It doesn’t need to be performed, for example we can only think of tossing a coin.