SOLUTION: A quiz cosists of 20 multiple-choice questions, each with 4 possible answers. For someone who makes random guesses for all of the answers, find the probability of passing if the mi
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Question 271787: A quiz cosists of 20 multiple-choice questions, each with 4 possible answers. For someone who makes random guesses for all of the answers, find the probability of passing if the minimum passing grade is 70 %
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A quiz cosists of 20 multiple-choice questions, each with 4 possible answers. For someone who makes random guesses for all of the answers, find the probability of passing if the minimum passing grade is 70 %
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Binomial Problem with n = 20 ; p = 1/4
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70% of 20 = 14
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P(x = 14) = 20C14(1/4)^14(3/4)^6 = 0.000025699...
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You could also find the probability
that the person answered "at least" 14 questions correctly.
P(14<= x <= 20) = 1 - binomialcdf(20,(1/4),13) = 0.000029512...
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Cheers,
Stan H.
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