what barriers&inequalities exist that may hinder opportunities for students2achieve their full potential in schools?Need help on my conclusion...

Of course, it is very difficult to know how to conclude a
paper when we cannot see all the information you are including or the conclusions you
have drawn from your data.

However, if I were writing this
conclusion, I would say something like this:

All students,
but particularly those from poorer backgrounds, face a number of challenges in achieving
their full potential in schools.  In the case of poorer children, they may well have a
homelife  or family situation that is not conducive to doing well in school.  In
addition, they may face some amount of unconscious prejudice on the part of teachers. 
Because of these factors, lower class students will often find it more difficult to
succeed in school.