Back to 5.3 Problems on Conditional Independence

5.3 Exercise 2

Avg difficulty 2.5

Suppose {A1,A2,A3} ci |C\left\{A_{1} , A_{2} , A_{3}\right\} ci \left|\right. C and ci |Ccci \left|\right. C^{c}, with P(C)=0.4P \left(C\right) = 0 . 4, and

P ( A i | C ) = 0 . 90 , 0 . 85 , 0 . 80 P ( A i | C c ) = 0 . 20 , 0 . 15 , 0 . 20 for i = 1 , 2 , 3 , respectively P \left(\right. A_{i} \left|\right. C \left.\right) = 0 . 90 , 0 . 85 , 0 . 80 P \left(\right. A_{i} \left|\right. C^{c} \left.\right) = 0 . 20 , 0 . 15 , 0 . 20 \text{for} i = 1 , 2 , 3 , \text{respectively}

Determine the posterior odds P(C|A1A2cA3)/P(Cc|A1A2cA3)P \left(\right. C \left|\right. A_{1} A_{2}^{c} A_{3} \left.\right) / P \left(\right. C^{c} \left|\right. A_{1} A_{2}^{c} A_{3} \left.\right).

Pfeiffer, Applied Probability, 5.3 Problems on Conditional Independence, exercise 2

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Adapted from Applied Probability © 2009 Paul E. Pfeiffer. Licensed under CC BY 3.0. Source: Applied Probability. Imported at revision d7a0420.