A multiple choice quiz consists of 20 questions, each with 3 possible equally likely answers. If a student guesses at the answer to each question, then the mean number of correct answers selected by the student is?
To calculate the mean number of correct answers selected by the student, we need to find the probability of guessing each question correctly and then multiply it by the number of questions.
In this case, each question has 3 possible equally likely answers, meaning that the probability of guessing the correct answer on any question is 1/3.
Since there are 20 questions, we can calculate the mean number of correct answers by multiplying the probability of guessing each question correctly (1/3) by the number of questions (20):
Mean number of correct answers = (1/3) * 20 = 20/3 = 6.67 (rounded to two decimal places)
Therefore, the mean number of correct answers selected by the student is approximately 6.67.