Probability

Abstract

In day to day life we make statements such as, it is very likely that Miss Good will be elected beauty queen in the coming beauty contest, tomorrow will probably be a sunny day, drug x is more of ective than drug y in curing disease A, the chances are almost nil that a man will live for ever, and so on. In all these statements there is a lack of certainty. Statistics and especially the theory of Probability play a vital role in making decisions in situations where there is a lack of certainty. There are three basic problems in the theory of probability, namely,

• (1) to describe the situation or to specify the set on which probability statements are made;

• (2) to define a numerical measure for a probability statement; and;

• (3) to evaluate numerically the probabilities for particular events.

Even though the palmists, astrologers and fortune-tellers of ancient India might have used a record of past events to predict the future, the recorded evidence of a systematic study of present day probability is that it is developed as a theory of games of chance in the 17th century when some ardent gamblers consulted mathematicians about dividing the stake money in cases of incomplete games.