SS6

Well done:

Answer explanation (in case you needed to guess).

The disease affected 1% of the 10,000 tested (100 people) however the test had sensitivity of 90% which means that it would detect 90 of those affected people. However the test had a specificity of 90%, so 10% of 9,900 tests would be false positives = 990. Total 90+990 = 1080 positive tests would be returned.

What is the positive predictive value of the previous test (sensitivity 90%, specificity of 90%, prevalence of the genetic variant of 1%)?