矩法正态性检验以三级动差为基础,计算偏度系数(g_1),反映资料的对称性,以四级动差为基础,计算峰度系数(g_2),反映资料的峰态。然后,对 g_1、g_2作 u 检验,判断其正态性。由于 g_1、g_2这两个统计量计算很麻烦,为简化计算,通常首先编制频数表,然后,以假定均数为中心,以组距为单位,计算各级动 The normality test of the moment method is based on the three-level motion difference, and calculates the skewness coefficient (g_1) to reflect the symmetry of the data. The kurtosis coefficient (g_2) is calculated based on the four-level motion difference and reflects the kurtosis of the data. Then, u test for g_1, g_2 to determine its normality. Since the statistics of g_1 and g_2 are computationally inconvenient, in order to simplify the calculation, the frequency table is usually first created. Then, the assumption is made as the center and the group distance is used as the unit.