《应用统计分析》答案详解高惠璇编著,北京大学数学教学系列丛书。
a+b a+c ∑ ( xti xi )( xtj x j ) = ∑ xti xtj nxi x j = a n n n t =1 t =1 1 1 = [an (a + b)(a + c)] = [a(a + b + c + d ) (a + b)(a + c)] n n ad bc = nn n
第六章 聚类分析
a+b ∑ ( xti xi ) = ∑ x nx = a + b n n t
=1 t =1 ( a + b) 1 = [n (a + b)] = (a + b)(c + d ) n nn n 2 2 ti 2 i
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