ABSTRACT
Probabilities, permutations and combinations are used daily in many different fields that range from gambling and games, to mechanical or structural failure rates, to rates of detection in medical screening. Use of standard deviation is widely used when results of opinion polls are described. An independent event is one in which the probability of an event happening does not affect the probability of another event happening. Conditional probability is concerned with the probability of say event B occurring, given that event A has already taken place. The addition law of probability is recognised by the word ‘or’ joining the probabilities. The multiplication law of probability is recognized by the word ‘and’ joining the probabilities. Bayes’ theorem is one of probability theory, and may be seen as a way of understanding how the probability that a theory is true is affected by a new piece of evidence.
