# Probability Theory

Probability is defined as a numerical measure which indicates the chance of occurrence. Assume that a coin is tossed the toss may result in the occurrence of head or a tail. The chances of head and tail are equal.

**Three systematic approaches are there in probability:****1)**. Classical approach**2)**. Empirical approach**3)**. Axiomatic approach.The above mentioned approaches has their own merits and demerits.

In the midst of such indefiniteness, predictions are made. This necessitated a systematic study of probabilistic happenings.

Probability theory is considered as a mathematical foundation for statistics and is used in quantitative analysis of large sets of data.

Probabilities are defined to obey certain assumptions and the probability value always lie between 0 and 1.