I had to made sure
I had to make sure / I have to make sureI had to made sure that I end up in a college not so big and not that small either, that has a very good community and has the option of research. I also found out I need to be in a liberal arts college because of the low student-faculty ratio.
Why you want a medium size college? what type community you look for? Also, what do you mean by "I also found out I need to be in a liberal arts college because of the low student-faculty ratio"????
They ask you;
Prompt: Given your interests, values, and goals, explain why Oberlin College will help you grow (as a student and a person) during your undergraduate years. (300 Words)
So you need to say why and how Oberlin answers your above concerns. It's not good enough to make statements without reasoning.