3 ms·
Let's see... Let's say you test 10,000 people, so about 100 actually have the disease. Since the test is only 99% accurate, only 99 of those will test positive.
by smartician 8y ago
Let's see... Let's say you test 10,000 people, so about 100 actually have the disease. Since the test is only 99% accurate, only 99 of those will test positive. Of the remaining 9,900 actually negative people, 99 will test falsely positive. So if you test positive, you have a 50% chance of actually having the disease?
- sykh 8y agoAs I understand the phrase, "99% accurate", this is correct. However, I gather that to statisticians this phrase could mean other things. I think the source of the ambiguity comes from whether or not everyone gets tested or something along those lines. To me the phrase should mean that when I test people who have the disease then 99% of the time I get a positive result and when I test people who don't have the disease then 99% of the time I get a negative result. That seems the most reasonable interpretation but I'm not a statistician.