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Solve this Bayesian problem. Jake has been arrested for petty larceny and his pa

ID: 3236133 • Letter: S

Question

Solve this Bayesian problem. Jake has been arrested for petty larceny and his parole officer suspects that it's to pay for his drug problem. He knows that about 3% of the population as cocaine or prescription painkiller dependency. Of those, an estimated 45% regularly steal to support their habit. Among those who do not have dependency, only about 1% have committed theft in the past 5 years. Given that Jake has been arrested, what are the chances he is using drugs? A general Bayesian equation: H = hypothesis, D = Data P(H|D) = P(D|H) times P(H)/P(D|H) times P(H) + P(D|NOTH) times P(NOTH)

Explanation / Answer

probabilty of Jack being arrested for theft =0.03*0.45+0.97*0.01 =0.0232

hence chances of using drugs, given arrested =0.03*0.45/0.0232=0.581897