I go to a private high school. It costs $15,000 a year. I therefore think it would be expected for it to be possible to meet my required credits by graduation, considering all circumstances normal.
Well, it's not.
Going into our senior year, all students have space for at least one elective and one free period. I decided to give up my free period to take another elective; an art class. I enjoy art, and I will be the editor of the yearbook, so that is where we typically work anyway. So, I filled my free period with an overload class, that doesn't count as a credit. On top of that, we had the electives lottery today. We were all assigned a random number in no particular order (not based on GPA or alphabetically, etc), and there were five elective classes. We were called up in order to choose our classes. I had one of the last ten picks. My personal first choice, sociology, filled up in a matter of minutes. My second choice, an additional english course, filled up before my turn as well. In fact, EVERYTHING was filled by the time it was my turn.
That's right. They didn't actually have enough classes for the students in our school. They didn't hire enough teachers for the classes next year. Good to know the $15,000 is being spent well.