SOLUTION: A multiple choice exam contains 50 questions. Each question has 5 choices, one of which is correct. We are interested in knowing the probability guessing exactly 18 questions corre

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Question 576666: A multiple choice exam contains 50 questions. Each question has 5 choices, one of which is correct. We are interested in knowing the probability guessing exactly 18 questions correctly.

(a) Is this a binomial experiment? Explain how you know.
(b) Use the correct formula to find the probability of guessing exactly 18 questions correctly out of the 50 questions. Show your calculations or explain how you found the probability.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A multiple choice exam contains 50 questions. Each question has 5 choices, one of which is correct. We are interested in knowing the probability guessing exactly 18 questions correctly.
(a) Is this a binomial experiment? Explain how you know
Trials are independent; p(correct) = 1/5 on each trial
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(b) Use the correct formula to find the probability of guessing exactly 18 questions correctly out of the 50 questions. Show your calculations or explain how you found the probability.
P(x = 18) = 50C18*(1/5)^18*(4/5)^32
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Cheers,
Stan H.
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