A screening test is used in the same way in two similar populations, but the proportion of false-positive results among those who test positive in population A is lower than that among those who test positive in population B. What is the likely explanation for this finding? Answer is The prevalence of disease is higher in population A.
Which the review answers are great, however this text lacks simple explanations as to why?
A false positive test for indicates the Type I error, also known as an "error of the first kind", ...
This solution explains why prevalence of a disease is higher in a population that has lower false-positive test results.