Question: Guessing Answers: Several economics students unprepared for a multiple choice quiz with 25 questions, and all of their answers are guesses. Each question has five possible answers, and only one of them is correct.

(a) Find the mean and standard deviation for the number of correct answers for each student.

(b) Would it be unusual for a student to pass by guessing and getting at least 15 correct answers? Why or why not?