Probabilities are between 0 and 1. a probability of 0 means that an event occur or that it is for the event to occur. if it is unlikely that the event will occur, then the probability of that event is . if it is equally likely that the event will occur or that the event will not occur, then the probability is . if it is very likely that the event will occur, then the probability of that event is . if the event will definitely occur, then the probability of that event is . a sample space has probability when all of the possible outcomes of the sample space have probabilities. closer to zero equal to one impossible real numbers one-half will not closer to one uniform equal