我们常在新闻和报纸上看到“百年一遇”和“千年一遇”这样的词,比如百年一遇的洪水,千年一遇的灾害,等等。而很多人都把这两个词想当然解释成一百年发生一次和一千年发生一次的事。其实从统计学上看,“百年一遇”却绝对不是一百年内只发生一次的意思,它真正的意思是事件发生的概率是百分之一。相应地,“千年一遇”则是指事件发生的概率为千分之一。事件发生的几率为百分之一和千分之一,这表明事件发生的概率很小。据此,很多人便以为,用到这两个 We often read in the news and in the newspapers such words as “once in a while” and “once in a while,” such as the once-in-a-century flood, the once-in-a-millennium disaster, and so on. Many people take it as a matter of course to interpret these two words as occurring once in a hundred years and once in a thousand years. In fact, from a statistical point of view, “once in a while” is definitely not the only one in a hundred years. What it really means is that the probability of an incident is one per cent. Correspondingly, “once in a while” refers to the probability that an event will occur as one thousandth. The probability of an incident is one percent and one thousandth, indicating that the probability of the incident is small. As a result, many people think that the two are used