https://twitter.com/SilentWarRoom/status/1353185429110009856?s=19
almost everyone cites statistics, and almost no one does so correctly, nor understands what they actually mean. for example, knowing that a medical diagnostic test is 90% accurate does NOT mean that an isolated positive test result translates into a 90% chance the test subject actually has the disease. in fact, without knowing, at least approximately, what percentage of the population at large is infected, the result is virtually meaningless.
allow me to digress. let's say you have 100 people, and 10 of them are actually infected and 90 of them are NOT infected. THINK about what would happen if you tested them all, using a test that was 90% accurate. of the 10 infected individuals you would get 9 positive results and 1 false negative. and of the 90 individuals who were NOT infected, you would get 81 negative results and 9 FALSE POSITIVES.
testing everyone from that group of 100 gives 9 positive results from the infected people AND 9 positive results from the uninfected people. SO…. if you randomly select 1 person from that group of 100 and they get a positive test, that means the odds that they ACTUALLY have the disease are FIFTY-FIFTY! NOT, 90%.
hopefully now you SHOULD understand, that without knowing at least approximately what percentage of the population at large is infected, an isolated test result is VIRTUALLY MEANINGLESS! if you test 100,000,000 people and NONE of them have the disease, you STILL get 10,000,000 positive results, and odds that EVERY one of them is a FALSE positive is ONE HUNDRED PERCENT!
got it?