Let’s say 1% of ppl have cancer at any given moment -
So if we test a random person, there is a 1% * 50% = 0.5% chance that person is tested positive for cancer because they have cancer.
And a 0.99% * 0.5% = 0.5% chance that a person is tested false positive.
This means if the test shows positive for somebody, it’s about 50-50 that they actually have cancer - correct?