观测结果的偶然误差时大时小,时正时负,随着观测次数增加,偶然误差的算术平均值将逐渐趋于0,因而,重复观测的次数越多,数据的均值越接近于真值。 观测数据作为样本,除了样本均值以外,还有一个参数——方差值得注意。它是样本各数据之间差异程 Occasional errors of the observed results are small and small, and positive and negative. As the number of observations increases, the arithmetic mean of the occasional errors gradually becomes zero. Therefore, the more the number of repeated observations, the closer the data mean to the true value . Observed data as a sample, in addition to the sample mean, there is a parameter - the variance worth noting. It is the difference between the data of the sample range