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An insurance company has a pap

[单选题]
An insurance company has a paper record and an electronic record for every claim. For an inaccurate paper record, 60% chances that the electronic record is inaccurate. For an inaccurate electronic record, 75% chances that the paper record is inaccurate. 3% of all the claims are inaccurate both in paper record and in electronic record. Pick one claim randomly, what are the chances that it is both accurate in paper record and in electronic record?
  • 97%
  • 94%
  • 68%
  • 65%
  • 35%
我说个简洁明了的方法:p为纸质文档,e为电子文档,0为错误,1为正确。
设总概率为1,四种情况表示为p(00)+p(01)+p(10)+p(11)=1。
依题意,有p(00)=3%,
                p(00)/p(00)+p(01)=60%
                p(00)/p(00)+p(10)=75%
可得四种情况分别为
00   3%
01   2%
10  1%
11  94%
发表于 2015-09-10 22:24:44 回复(4)
设 A 为纸质记录不靠谱;B为 电子记录不靠谱;
题中给出的条件为:
P(B逆|A逆)=60%
P(A逆|B逆)=75%
P(A逆B逆)=3%
求P(AB)
P(B逆)=p(A逆B逆) / p(A逆 | B逆) = 3% / 75 % = 4 %
P(A逆)=p(A逆B逆) / p(B逆 | A逆) = 3% / 60 % = 5 %
P(AB)= 1-P(A逆)-P(B逆)+P(A逆B逆)=1- 5% - 4 % + 3%=94%,
发表于 2015-08-17 10:35:05 回复(2)
假设A表示事件:书面不正确;B表示事件:电子不正确。那么A-表示事件:书面正确;B - 表示事件:电子正确(这里-就是指代对立事件)
根据题意,已知:
P(B|A)=0.6;
P(A|B)=0.75;
P(AB)=0.03;
那么根据公式就有:
P(A)=P(AB)/P(B|A)=0.05;
P(B)=P(AB)/P(B|A)=0.04;
由此可得P(A并B)=P(A)+P(B)-P(AB)=0.05+0.04-0.03=0.06
而题目叫我们求的是书面和电子都正确的概率,也就是事件A-B-的概率。
根据公式又可以知道,P(A - B - )=P((A并B)的对立)=1-P(A并B)=1-0.06=0.94
发表于 2017-06-26 12:50:21 回复(0)
只要电子和纸质的有一个不准确则肯定两个都不准确,直接1-3%-3%=94%
发表于 2015-08-22 21:51:20 回复(0)
算的时候靠谱和不靠谱算反了。。囧
发表于 2015-09-04 12:06:02 回复(0)
设 A 为纸质记录不靠谱;B为 电子记录不靠谱;
题中给出的条件为:
P(B逆|A逆)=60%
P(A逆|B逆)=75%
P(A逆B逆)=3%
求P(AB)
P(B逆)=60%*3%
P(A逆)=75%*3%
P(AB)=1-P(A逆+B逆)=1-P(A逆)-P(B逆)+P(A逆B逆)=1-(1.35)3%+3%=1-0.35*%3=98.95%,
我这个过程哪里有问题?
发表于 2015-08-15 09:46:48 回复(2)
解析:B选项94%是正确选项
发表于 2014-10-25 00:26:06 回复(0)
b
发表于 2014-10-23 18:52:21 回复(0)