For example, if you have cancer you might have a 90% chance of testing positive for cancer, but if you test positive for cancer you might have only a 10% chance of actually having cancer because cancer is very rare.
You might have a 90% chance of testing positive for cancer. This is for example. You have cancer. You might have only a 10% chance of actually having cancer because cancer is very rare. This is for example. You test positive for cancer.