Question 325498
If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices. 
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Binomial Problem with n = 20 and p = 1/4
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P(x=4) = 20C4(1/4)^4(3/4)^16 = 0.1897
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Cheers,
Stan H.