<PRE><B>Question 329409</B>
 A Multiple-choice test has 15 questions with each having 4 possible answers with one correct. Assume a student randomly guesses the answer to every question.
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Binomial Problem with n=15 and p = 1/4
-------- 
a. What is the probability of getting exactly 5 correct answers?
P(x= 5) = 15C5*(1/4)^5*(3/4)^10 = binompdf(15,1/4,5) = 0.1651
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b. What is the probability of getting less than 6 correct answers? 
P(less than 6) = binomcdf(15,1/4,5) = 0.8516
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Cheers,
Stan H.</PRE>