Question

请找一下规律：1/3、-2/15、3/35、-6/63接下来应该怎么填

Answer 1

样本X1,X2,……Xn平均数为5,方差为3,则,5 = [X1 + X2 + ...+ Xn]/n 3 = [(X1 - 5)^2 + (X2 - 5)^2 + ...+ (Xn - 5)^2]/n 因此,[3(X1 - 1) + 3(X2 - 1) + ...+ 3(Xn - 1)]/n = 3[X1 + X2 + ...+ Xn]/n - 3 = 15 - 3 =...