Question 949332: A student guesses blindly on a 20-question multiple choice test. If each question has 4 answer choices (only one of which is correct), what is the probability that the student will answer exactly 10 questions correctly?
(I have tried literally everything, Ive tried formulas from online and nothing seems to be correct. Please help!)
Thank you so much,
Sierra
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A student guesses blindly on a 20-question multiple choice test. If each question has 4 answer choices (only one of which is correct), what is the probability that the student will answer exactly 10 questions correctly?
---------------------
Binomial Problem with n = 20 and p(correct) = 1/4
-----
P(x = 10) = 20C10(1/4)^10*(3/4)^10 = binompdf(20,1/4,10) = 0.00992
-----------------
Cheers,
Stan H.
-----------------
|
|
|
