Jason inherited a piece of land from his great-uncle. Owners in the area claim that there is a 45% chance that the land has oil. Jason decides to test the land for oil. He buys a kit that claims to have an 80% accuracy rate of indicating oil in the soil. What is the probability that the land has no oil and the test shows that it has oil?

So this is how I did it but my answer was wrong.
(0.45*0.55)/(0.45*0.55)+(0.55*0.80)
answer 0.36 WRONG???

The answers listed are
0.09
0.11
0.44
Did I do something wrong or is this another bad question?

Question

Jason inherited a piece of land from his great-uncle. Owners in the area claim that there is a 45% chance that the land has oil. Jason decides to test the land for oil. He buys a kit that claims to have an 80% accuracy rate of indicating oil in the soil. What is the probability that the land has no oil and the test shows that it has oil?

So this is how I did it but my answer was wrong.
(0.45*0.55)/(0.45*0.55)+(0.55*0.80)
answer 0.36 WRONG???

The answers listed are
0.09
0.11
0.44
Did I do something wrong or is this another bad question?

ganeshie8 · Answer

this is not an inference problem, so you dont need to use bayee's theorem

ganeshie8 · Answer

just use the prior probabilities directly

ganeshie8 · Answer

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