【VIP专享】The Evolution of Probability Theory

The Evolution of Probability Theory

Seraphim 17 Oct 2011 The Origin

?A gambler's dispute in 1654 led to the creation of a mathematical theory of probability . ?Chevalier de Méré, a French nobleman with an interest in gaming and gambling questions, called Pascal's attention to an apparent contradiction concerning a popular dice game. The game

consisted in throwing a pair of dice 24 times; the problem was to decide whether or not to bet even money on the occurrence of at least one \established gambling rule led de Méré to believe that betting on a double six in 24 throws would be profitable, but his own calculations indicated just the opposite.

?When Pascal knew his puzzles, he exchanged letters with another famous mathematician Fermat. ?Pascal and Fermat firstly formulated the some fundamental principles of the probability theory. No general theory was developed before this famous correspondence. The Branches of Probability

?There are many different branches of probability , which have different definitions of the probability. Those definitions describe different aspects of the probability and some have crucial influence for the modern probability. The followings are some well-known definitions of probability. ?Classical Definition of Probability: The probability of an event is the ratio of the number of cases favorable to it, to the number of all cases possible when nothing leads us to expect that any one of these cases should occur more than any other, which renders them, for us, equally possible. ?The classical definition of probability is identified with the works of Pierre-Simon Laplace.

This definition is essentially a consequence of the principle of indifference. If elementary events are assigned equal probabilities, then the probability of a disjunction of elementary events is just the number of events in the disjunction divided by the total number of elementary events. ?There are some disputes about the classical definition. For example, if the number of all possible cases is infinite, the probability can not be determined by the classical definition. What’s more ,this situation is more practical in real life. So another definition was created due to the defects of classical definition.