There are 60 questions on a multiple choice exam. For each question there are 5 choices to choose from, and there is only one correct choice for each question. Find the mean (expected value) and variance for the number of questions you answer correctly by making random guess.
Added by Eugene H.
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We can model this situation using a binomial distribution, since there are a fixed number of trials (60 questions), each with two possible outcomes (correct or incorrect), and a constant probability of success (1/5 chance of guessing correctly). For a binomial Show more…
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