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问题: =[0.2×(40%-10.6%)2+0.5×(10%-10.6%)2+0.3×(-8%-10.6%)2]1/2 =16.64%

请列出怎样子在一步一步计算的步骤,谢谢

解答:

[0.2×(40%-10.6%)^2+0.5×(10%-10.6%)^2+0.3×(-8%-10.6%)^2]^(1/2 )
=[0.2×29.4%^2+0.5×(-0.6%)^2+0.3×(-18.6%)^2]^(1/2)
=(0.0172872+0.000018+0.0103788)^(1/2)
=0.027684^(1/2)
=0.166385
=16.64%