For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the infection and negative for those who did not have the infection?
(1) Of those who tested positive for the infection, did not have the infection.
(2) Of those tested for the infection, 90 percent tested negative.
这个应该是,有一种测试,如果得病了的人如果结果为正,或者没得病的人结果为负,就是测试正确 - (误诊的情况就是不正确. 问你多少百分比的人是测试正确
你的1选项是不是有信息漏了?看起来逗号后面应该有个数字 |