It is a value between zero and one, inclusive, describing the relative possibility (chance or likelihood) an event will occur in the future. As there is uncertainty in decision making, it is important to evaluate scientifically known risks involved. For this evaluation, probability theory (which is often referred to as the science of uncertainty) is helpful. The use of probability theory allows the decision maker with only limited information to analyze the risks and minimize the gamble inherent. For example, in marketing a new product or accepting an incoming shipment possibly a shipment contains defective parts.