A student is unprepared for a multiple-choice quiz with 10 questions and all their answers are random guesses. Each question has 5 possible answers and only one is correct, so they have one chance in 5 of getting any given question correct.

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

b) Would it be unusual for this type of guessing student to get at least 7 right? Why or why not?