A crime has occured in Carborough, involving a taxi. The police interviewed an eyewitness, who stated that the taxi involved was blue.

The police know that 85% of taxis in Carborough are blue, the other 15% being green. They also know that statistically witnesses in these situations tend to be correct 80% of the time - which means they report things wrong the other 20% of the time.

What is the probability that the taxi involved in the crime was actually blue?

is my problem.

wanda wye is investigating a murder on Cabin Island. On this island, interviewing witnesses is a real pain, because island inhabitants only tell the truth 1/3 of the time. she begins the questions with local resident, Isaw Itall. he says, 'bob is the murder.' she knows this could be a lie, but immediately another islander comes and and says, 'isaw is telling the truth.' she now believes she has a truth probability of 2/3 and arrests bob. Is Wanda correct? explain by proving exactly wwhat the probability is that Isaw's statement is true.

i have been going nuts over this one for an hour so far. and each time i ask my teacher, he says im going in the wrong direction. any help is greatly appreciated.  

Posted by sean on 2007-02-20 23:17:08