If I know the probability of a lake being polluted is .14 and the probability of it being naturally polluted is .25, how do I find the probability that it is naturally polluted? I have played with this for a long time and still have no idea how to calculate it. In fact, I'm not even sure where to start. Any guidance would be greatly appreciated.(adsbygoogle = window.adsbygoogle || []).push({});

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Probability question

**Physics Forums | Science Articles, Homework Help, Discussion**