5.1.设抽样得到样本观测值为 38.240.042.437.639.241.044.043.238.840.4 计算样本均值、样本方差、样本标准差与样本二阶中心矩 解:x=1 x;=40.5 n i= S 2 nx2)=4.66,S=√4.66=2.1587 n U,=1(xx)2=4.1945.1. 设抽样得到样本观测值为 38.2 40.0 42.4 37.6 39.2 41.0 44.0 43.2 38.8 40.4 计算样本均值、样本方差、样本标准差与样本二阶中心矩 . ..)( ( ,..,.) ;. 1944 1 4 66 4 66 2 1587 1 1 40 5 1 2 1 2 2 1 2 2 1 = =− ===− − = = = ∑ ∑ ∑ = = = xx n U xnx S n S x n x n i i n i n i i i 解：