h**6
发帖数: 4160 | 1 假设阳性对x个，阴性错y个，则x+y=3
P{x=3,y=0} = 3C5*0.8^3*0.2^2*0C5*0.9^5*0.1^0 = 0.120932352
P{x=2,y=1} = 2C5*0.8^2*0.2^3*1C5*0.9^4*0.1^1 = 0.01679616
P{x=1,y=2} = 1C5*0.8^1*0.2^4*2C5*0.9^3*0.1^2 = 0.00046656
P{x=0,y=3} = 0C5*0.8^0*0.2^5*3C5*0.9^2*0.1^3 = 0.000002592
全加起来就是了 P = 0.138197664 |
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