农业科学试验中所研究的现象,大多属于随机现象,往往会出现误差。这种误差,实际上是许许多多相互独立的、微小的随机误差的总和(不包括观测和计算中产生的系统误差和过失误差)。实践和理论告诉我们,这种由个数很多的随机误差所组成的整体偏差的概率分布是服从正态(或称常态)分布的。这就是概率论中的中心极限定理。在实际工作中研究和分析符合正态分布的整体偏差的每个个体的概率分布情况,对于验证科学试验结果的正确性是十分重要的。在数理统计中,如果其他随机误差(非处理误差)在总偏差中的概率分布小 The phenomena studied in agricultural science experiments are mostly random phenomena, and errors often occur. This error, in fact, is the sum of many independent and minor random errors (excluding systematic errors and errors of errors in observations and calculations). Practice and theory tell us that the probability distribution of the global deviation composed of a large number of random errors is subject to the normal (or normal) distribution. This is the central limit theorem in probability theory. It is very important to verify and verify the correctness of the results of scientific experiments by studying and analyzing the probability distribution of each individual that meets the global deviation of normal distribution in practical work. In mathematical statistics, if the probability distribution of other random errors (non-processing errors) in the total deviation is small