如果一个人看A书的概率是10%,看B书概率是20%,那他同时看A,B的概率是10%乘20%对吗?那为什么下面这条题目我用的概率相乘得不到答案?A student going to common room reads Private Eye with probability0.75,Private E
来源:学生作业帮助网 编辑:作业帮 时间:2024/11/24 23:35:38
如果一个人看A书的概率是10%,看B书概率是20%,那他同时看A,B的概率是10%乘20%对吗?那为什么下面这条题目我用的概率相乘得不到答案?A student going to common room reads Private Eye with probability0.75,Private E
如果一个人看A书的概率是10%,看B书概率是20%,那他同时看A,B的概率是10%乘20%对吗?
那为什么下面这条题目我用的概率相乘得不到答案?
A student going to common room reads Private Eye with probability0.75,Private Eye but not the Daily Express with Probability0.65.The student reads neither with probability 0.2
Find the probability that the student reads the Daily Express but not Private Eye.
如果一个人看A书的概率是10%,看B书概率是20%,那他同时看A,B的概率是10%乘20%对吗?那为什么下面这条题目我用的概率相乘得不到答案?A student going to common room reads Private Eye with probability0.75,Private E
对于两个互不相干的独立事件,其同时发生的概率是各自发生的概率的乘积.从该题的描述看,阅读Private Eye和 Daily Express不是相互独立的事件,所以不能用概率相乘来解决
只看Private Eye 是0.65, 只要看了Private Eye是0.75,所以既看了Private Eye又看了Daily Express的概率是0.75-0.65=0.1
那么根据所有独立事件概率之和为1, 只看Private Eye + 只看Daily Express +既看PE又看DE + 既不看PE 又不看DE = 1
所以0.65+只看DE+0.1+0.2=1...
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只看Private Eye 是0.65, 只要看了Private Eye是0.75,所以既看了Private Eye又看了Daily Express的概率是0.75-0.65=0.1
那么根据所有独立事件概率之和为1, 只看Private Eye + 只看Daily Express +既看PE又看DE + 既不看PE 又不看DE = 1
所以0.65+只看DE+0.1+0.2=1
那么只看Daily Express的概率是0.05
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概率是相加/2 就是 (10%+20%)除以2
而不是相乘~~!!