<PRE><B>Question 576666</B>
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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