A multiple-choice test contains 25 questions, each with 4 answers. Assume a student just guesses on each question. (a) What is the probabili

Question

A multiple-choice test contains 25 questions, each with 4 answers. Assume a student just guesses on each question. (a) What is the probability that the student answers more than 20 questions correctly

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Amity 5 months 2021-08-25T07:39:14+00:00 1 Answers 16 views 0

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  1. thucuc
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    2021-08-25T07:40:19+00:00
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    Answer:

    9.68*10^-10

    Step-by-step explanation:

    The problem above can be solved using the binomial probability relation :

    Where ;

    P(x = x) = nCx * p^x * q^(n-x)

    n = number of trials = 25

    p = 1/4 = 0.25

    q = 1 – p = 0.75

    x = 20

    P(x > 20) = p(x = 21) + p(x = 22) +.. + p(x = 25)

    Using the binomial probability calculator to save computation time :

    P(x > 20) = 9.68*10^-10

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