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I'm not sure why you're getting snarky. I'm really not having a go. I've been honestly asking why the results you're claiming you get are the results (how a test with n% accuracy for the person being tested on can drop down to 66% or whatever based on the amount of people who have the sickness independently from the test being administered).
I'll do the math and see what happens. Maybe. We'll see how much I want to ignore work tomorrow.
Greenbank
OK, so if you have 10,000 people and you know exactly 500 of them are positive. That's 5%. So 95% are negative.
Nopw imagine you have a test that where sensitivity and specificity are 95%.
When you test the 9500 people who are negative how many -ves and how many +ves do you expect to get?
When you test the 500 people who are positive how many +ves and how many -ves do you expect to get?
What is the accuracy for those who were negative?
What is the accuracy for those who were positive?
What is the accuracy for those that received a negative result?
What is the accuracy for those that received a positive result?
What is the accuracy of the test?
(Bonus question: Why are none of the last 3 answers 95%?)