Hazard Risk Assessment Fundamentals
Probabilities are nonnegative numbers associated with the outcomes of socalled randOln experiInents. A randoln experiInent is an experiment whose outconle is uncertain. Exmnples include throwing a pair of dice, tossing a coin, counting the nUlnber of defectives in a smnple froln a lot of lnanufactured itenls, observing the tilue to failure of a tube in a heat exchanger, a seal in a pwnp, or a bus section in an electrostatic precipitator. The set of possible outcolues of a randonl experiInent is called the san/pie space mld is usually designated by S. Then P(A), the probability of event A, is the SUlll of the probabilities assigned to the outCOlnes constituting the subset A of the smnple space S.