I'll do your homework for you. Singapore, who is kicking our butt in education, has a standard class size of 60 students. Now I'll speak from experience.
 in 1977 my mother pulled me from OPS, because this problem has been on going even before then, and sent me to England to go to school. England graduated students at 16 years of age, and with the equivalent of our freshman college aptitude. That's 3 years ahead of us at 16. I had to be bumped up 2 grades to be with students my own age.
 I had class sizes of 35-45 students. England was preparing me for college at 17, where I can expect class sizes of 100-150 students.
  The real problem is twofold. #1 our curriculum is trying to teach 95 and less IQ students subjects they will never, ever, be able to grasp. Just read their posts on CC. #2 most of our educators cannot teach at this level regardless the class size.