a prospector thinks there is an even (50-50) chance that his property contains oil. any property suspected to have oil can go through two independent tests. the first test is 80% reliable; if there is oil on the property, it reports positive 80% of the time, and it reports negative 80% of the time whenener there is no oil. for the second test, it reports positive 75% of the time when there is oil, as well as reporting positive 50% of the time when there is no oil. what is the probability the property has oil, given that both tests report positive? assume event a: first test reports positive; event b: second test reports positive; event o: the property has oil.