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匿名 發問於 教育及參考書小學及中學教育 · 9 年前

probability

an association wants to conduct a telephone interview to collect public opinion on introducing a sales tax in hk.the probability of a successful telephone interview where valid data are collected is 0.1.suppose that 50 calls were made on a certain morning.

find the probabilities that

1.all interview attempts fail

2.there is at least one successful interview

1 個解答

評分
  • wkho28
    Lv 7
    9 年前
    最愛解答

    1. The probability of a successful telephone interview is 0.1.

    The probability that an interview attempt fails is: 1-0.1=0.9.

    The probability that 2 interview attempts fail is:

    0.9X0.9=(0.9)^2.

    .

    .

    .

    The probability that all 50 interview attempts fail is:

    (0.9)^50=0.00515

    2. The probability that there is at least one successful interview is:

    1-0.00515=0.99485 (~0.995)

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