问一道题：NO.PZ2019040801000074 [ FRM I ]

NO.PZ2019040801000074问题如下Company A is a cru oil supplier. analyst, you shouljue whether Company A will have new velopment estimating Company A's largest customer B company will whether increase the orr volume or not. You estimate ththe probability thCompany B will increase the orr volume is 30%. If Company B es increase the orr volume, Company A will have a new velopment probability of 80%. If Company B es not increase the orr volume, then Company A will have a new velopment probability of only 10%. After that, you scoverethcru oil supplier company A hstartea new velopment. Unr this contion, whis the probability thyou estimate the company B to increase the orr volume?A.18.59%.B.22.58%.C.77.42%.12.45%.C is correct.考点Bayes' Formula解析涉及到贝叶斯公式的题目，首先要定义事件。定义事件B1——Company B will increase the orr volume，B2——Company B will not increase the orr volume，A1——Company A will start a new velopment，A2——Company A will not start a new velopment根据已知条件P(B1)=30%，P(A1|B1)=80%，P(A1|B2)=10%。求的是P(B1|A1)。根据贝叶斯公式，P(B1|A1)=P(A1B1)/P(A1)，所以接下来分别求P(A1B1)和P(A1)。由P(B1)=30%，得到P(B2)=70%。P(A1B1)=P(A1|B1)*P(B1)=80%*30%=0.24P(A1B2)=P(A1|B2)*P(B2)=10%*70%=0.07所以P(A1)=P(A1B1)+P(A1B2)=0.31所以P(B1|A1)=P(A1B1)/P(A1)=0.24/0.31=77.42% 这道题好像不能完全用贝叶斯画图解题对吗？主要是占比的问题

22.58%. 77.42%. 22.58%. C is correct. 考点Bayes' Formula 解析涉及到贝叶斯公式的题目，首先要定义事件。 定义事件B1——Company B will increase the orr volume，B2——Company B will not increase the orr volume， A1——Company A will start a new velopment， A2——Company A will not start a new velopment 根据已知条件P(B1)=30%，P(A1|B1)=80%，P(A1|B2)=10%。求的是P(B1|A1)。 根据贝叶斯公式，P(B1|A1)=P(A1B1)/P(A1)，所以接下来分别求P(A1B1)和P(A1)。 由P(B1)=30%，得到P(B2)=70%。 P(A1B1)=P(A1|B1)*P(B1)=80%*30%=0.24 P(A1B2)=P(A1|B2)*P(B2)=10%*70%=0.07 所以P(A1)=P(A1B1)+P(A1B2)=0.31 所以P(B1|A1)=P(A1B1)/P(A1)=0.24/0.31=77.42% 老师这道题能否详细讲解一下