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想做蜜蜂的猫咪 · 2022年09月24日

在视频中老师提到可以用bayes只有在两种情况下，这道题是两种吗，不是3种吗，股票还有表现好中坏之分

  1. CFA I
  2. Quantitative

NO.PZ2015120604000076

问题如下：

According to the above table, and we are informed that the performance of next day is good, what is the probability of today's performance is good?

选项：

A.

0.74.

B.

0.28.

C.

0.67.

解释：

C is correct.

We can use Bayes' formula to solve this problem.

A: today's performance is good.

B: next day's performance is good.

P(A|B)=P(B|A)*P(A)/P(B)=0.7×0.4/(0.4×0.7+0.2×0.3+0.4×0.2)

P(B|A)*P(A)=0.7×0.4=0.28

P(B)=0.4×0.7+0.2×0.3+0.4×0.2=0.42

P(A|B)=0.67

在视频中老师提到可以用bayes只有在两种情况下，这道题是两种吗，不是3种吗，股票还有表现好中坏之分

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1 个答案

星星_品职助教 · 2022年09月25日

同学你好，

两种是90%以上题目的情况。三种也可以，只要是这种分叉的形式都可以用。

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