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# 請統計學高手幫忙解題

An import-expert firm has a 45% chance of concluding a deal to export agricultural equipment to a developing nation if a major competitor does not bid for the contract, and a 25% probability of concluding deal if competitor does bid for it. It is estimated there is a 40% chance that the competitor will submit a bid for the contract .

A. what is the probability of concluding a deal ?

B. If a fir secures the deal, what is the probabliity that the competitor had also put in a bid.

A 答案是0.37

B 答案是0.2703

### 1 個解答

• 1 0 年前
最佳解答

Ans：

Let the event that the import-expert firm concluds a deal to export agricultural equipment to a developing nation be W. On the other hand, let the event that the import-expert firm does not

conclud a deal be NW.

Let the event that the major competitor bids for the contract be B. On the other hand, let the major competitor does not bid for the contract be NB.

According to prob given by the question,

Pr( W| NB)=0.45, Pr( W| B)=0.25, Pr(B)=0.4

(1)Pr(W)= Pr( W, B)+Pr( W, NB)=Pr(B)*Pr( W| B)+Pr(NB)*Pr( W| NB)=0.4*0.25+0.6*0.45=0.37

(2)Pr( B| W)=Pr( B,W)/Pr(W)=0.4*0.25/0.37=0.2703.

參考資料： 自己