A truth serum given to a suspect is known to be 86 percent reliable when the per

Question

A truth serum given to a suspect is known to be 86 percent reliable when the person is guilty and 98 percent reliable when the person is innocent in other words, 14 percent of the gutty are judged innocent by the serum and 2 percent of the innocent are judged guilty. If the suspect was selected from a group of suspects of which only 9 percent are guilty of having committed a crime, and the serum indicates that the suspect is guilty of having commuted a crime, what is the probability that the suspect is innocent portability 0187

Explanation / Answer

A: event that the suspect is guilty of the crime

B:event that the serum reveals that the suspect is guilty

P(A)=0.09 and P(not A)=1-0.09=0.91

P(B given A)=0.86 and therefore P(not B given A)=1-0.86=0.14

P(not B given not A)=0.98 and therefore P(B given not A)=0.02

We need , P(not A given B) which is P(B given not A)*P(not A)/(P(B given not A)*P(not A)+P(B given A)*P(A))

=(0.02*0.91)/(0.02*0.91+0.86*0.09)=0.191

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.