Sample Space 样本空间 The set of all possible outcomes of a statistical experiment is called the sample space
Event 事件 An event is a subset of a sample space
certain event(必然事件): The sample space S itself, is certainly an event, which is called a certain event, means that it always occurs in the experiment
impossible event(不可能事件): The empty set, denoted by, is also an event, called an impossible event, means that it never occurs in the experiment
Probability of events (概率) If the number of successes in n trails is denoted by s , and if the sequence of relative frequencies /s n obtained for larger and larger value of n approaches a limit, then this limit is defined as the probability of success in a single trial
“equally likely to occur”------probability(古典概率) If a sample space S consists