Question 583349: Please help me find the Probability: A student guesses on every question of a multiple-choice test that has 9 questions, each with 5 possible answers. What is the probability that the student will get at least 7 of the questions right?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A student guesses on every question of a multiple-choice test that has 9 questions, each with 5 possible answers. What is the probability that the student will get at least 7 of the questions right?
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Binomial Problem with n = 9 ; p(correct)=1/5 ; p(wrong)=4/5
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P(7<= x <=9)
= 1 - P(0<= x <=6)
= 1 - binomcdf(9,1/5,6)
= 0.000314
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Cheers,
Stan H.
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