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edmilson28 · 2017年06月05日

NO.PZ2015121802000021

  1. CFA I

请问这里为啥使用样本方差，而不是标准方差？

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源_品职助教 · 2017年06月05日

同学你是不是想问为什么没有用“总体方差”，我印象里没有标准方差这个东西。

通常情况下，一个投资的投资期远不止5年，所以这题中所列举的5年投资期只是总体投资时间中的一个样本而已。故题目要求的是样本方差。


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