不少作者在计算病死率,百分比等相对数时,常把相对数算得过细,一共才几十例,可算到小数后两三位数字。数据位数多并不等于是精确。30例以下的样本,只写例数即可,不必求百分数之类。30～100例的样本,相对数只能有两位有效数字,为26％、3.7％,一般来说,样本有几位数字,相对数 Many authors often calculate the relative number of death rates, percentages, etc., and often count the relative numbers as too small. There are only a few dozen cases, and they can be counted as two or three decimal places. More than the number of data does not mean that it is accurate. For samples of less than 30 cases, only the number of cases can be written. There is no need to calculate the percentage. For 30 to 100 samples, the relative number can only have two significant figures, which are 26% and 3.7%. Generally speaking, there are several figures in the sample, relative numbers.