[問題]GWD15/ Q-35

[evelyn_yeh]

Q35:
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.

ANS(E)

版上大大:
這題我真的敗了~~完全不知如何解題
請大大們給一點clue吧??

[chour]

Q35:
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, 1/8 did not have the infection.
(2) Of those tested for the infection, 90 percent tested negative.

ANS(E)

求某檢驗的正確率
(1)呈有病反應的人裡,1/8其實沒病
(2)全部受測者中,90%測出無病反應

即使考慮兩個條件
仍須知道,測出無病反應的受測者中,有多少比率是有病或無病的,才算資料充分