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kevinzhu · 2019年11月25日

问一道题：NO.PZ2015121802000021 [ CFA I ]

  1. CFA I
  2. Portfolio

问题如下图：

选项：

A.

B.

C.

解释：

Sample variance = 78.8/(5 - 1) = 19.7 为什么要除以n-1?
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星星_品职助教 · 2019年11月26日

同学你好，

这里要求的是“样本”的方差。回忆一下数量里的内容，总体方差分母除以的是n，而样本除以的是n-1，这么做的目的是因为只有除以n-1才是一个最好的估计量。

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