[請益] 數學題(統計)翻譯

[Ertkkpoo (water)]

大家好

有兩個問題想請教一下，我只列出題目，沒有列問題，因為我的疑問只是在題意部分

1.
    To reduce theft, the Merdeth Company screens all its employees with

    a lie detector test that is known to be correct 90 percent of the time

    (for both guility and innocent subjects). George Meredeth decides to fire

    all employees who fail the test. Suppose 5 percent of the employees are

    guility of theft.

    問題見黃句，我不太懂這句的意思是不是指 機器會有90%的準確機會去找出

    真正說謊者，而10%機會可能會誤把無辜者判斷為說謊者?

    也就是我可以列式成 P(判為說謊者|真正說謊者)=90%?

    P代表機率，上述表示法為條件機率

2.
    A diagnostic test for a disease is said to be 99% accurate in that

    if a person has the disease, the test will detect it with probability 0.9.

    Also, if a person does not have the disease, the test will report that he

    or she does not have it with probability 0.9. Only 1% of the population

    has the disease in question. If a person is chosen at random from the

    population and the diagnostic test indicates that she has the disease,


    黃句的意思是不是指  P(被檢查出有病|真正有病)=0.9? 但那個99%又是指?



謝謝大家

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推 l10nel:1: 記得題目説both，所以除了說謊者的條件機率，還有：
→ l10nel:P(判為説實話|真正說實話者)=90%，兩式皆成立
→ l10nel:2: 你說對了，和1一樣的情況。99%指P(無病)=99%，或者
→ l10nel:P(有病)=1%，兩者是補集。
→ dunchee:2. 如果你沒有抄錯，那麼就是原出處有問題 99% <-> 0.99
→ dunchee: http://ppt.cc/F@Gk
推 l10nel:的確，第二題的「99% accurate」應改為90%
→ Ertkkpoo:謝謝大家，可能是題目有問題，看了好久還是不懂題意
→ l10nel:題目敘述應該不難吧，還有哪裡不懂？還是不知怎麽解題？