Question 450023
Suppose a student takes a multiple choice test with 10 questions and he randomly guesses the answers (say he forgot to study). Each questions has five choices but only one right answer. What is the probability that he gets at least 7 right out of the 10 questions.
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Binomial Problem with n = 10 and p = 1/5
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P(5<= x <=10) = 1-P(0<= x <=4) = 1-binomcdf(10,1/2,4) = 0.6230
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I used a TI-84 to get the numbers.
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Cheers,
Stan H.
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