Re: [理工] [機率]-機率
※ 引述《AAJJBurnett (叫我投手)》之銘言：
: A store sells four brands of VCRs.The least expensive brand B1 accounts
: for 40% of the sales. The other brands(in order of their price) have the
: following percentages of sales:B2,30%;B3,20%;and B4,10%.The respective
: probabilities of needing repair during warranty are 0.10 for B1,0.05 for
: B2, 0.03 for B3, and 0.02 for B4. A randomly selected purchaser has a VCR
: that needed repair under warranty. What are the four conditional
: probabilities of being brand Bi, i=1,2,3,4 ?
令Y為送修事件
0.10, i=1
0.05, i=2
P（Y｜Bi）= 0.03, i=3
0.02, i=4
0.4, i=1
0.3, i=2
且P(Bi)= 0.2, i=3
0.1, i=4
可依序得，P（Y╭╮B1）=0.10*0.4=0.04 ...etc
將得到的四個機率總合，可得到P(Y)
而 P(Y╭╮B1）
------------ = P(B1｜Y)....此求法得依序得其它條件機率。
P(Y)
有錯請指教, 謝謝~
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10/06 10:26, , 1F
10/06 10:26, 1F
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