SOLUTION: A quiz consists of 30 true or false questions. If the student guesses on each question, what is the mean and the standard deviation of the number of correct answers?

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Question 1178697: A quiz consists of 30 true or false questions. If the student guesses on each
question, what is the mean and the standard deviation of the number of correct
answers?
Answer by htmentor(1343) About Me  (Show Source):
You can put this solution on YOUR website!
For each question, the probability of answering correctly is 0.5, and the
questions are independent of each other. This situation is described by
a binomial probability distribution. The mean of a binomial distribution
is mu = n*p, where p is the probability of a success and n is the number of
trials. Thus mu = 0.5*30 = 15.
The standard deviation is given by sqrt(np(1-p) = sqrt(30/4) = 2.739