No, not solely dependent on the school.  As the attached model shows, there are MANY factors affecting student learning.  Some are related to the school, but many are not.  

I have also linked to the full paper.  It is about Computer Assisted Language Learning, but I think that the discussion of factors affecting student success spans disciplines.

Data CEM-Color

Article Environmental factors affecting Computer Assisted Language L...

 Thanks Michael 

I agree with Michael but the great bit of closing the gap can be done at school. The attached discussed the need to accommodate the diverse backgrounds of students so that they are given the best advantage to succeed.

many thanks,

Debra

Article One Style Does Not Fit All: Facilitating Cultural Difference...

It is a big NO. It does not solely depend on the students. Students now a days don't want to go an extra mile at all and want to be always spoon-fed.

In as much as the school has a role to play, the students have a big responsibility of learning and delivering what is expected of them in order to succeed., and this is how the gap can be bridged.

Further, success is not limited to a specific class of people but to those who strive for it. Students must strive and think outside the box and this is the only way the achievement gap can be bridged.

Laziness is killing today's students and this can lead to no or poor achievement on their part.

The School on the other hand would have to provide Quality Education.

I really like this question.  I feel my school is inadequate in this area.  I support the case of multiple intelligence.  My school is a community college that focuses more on mainstream academics and tend to offer less energy to the other skills, for example, technical education.

Really Harshvardhan Singh, they are very helpful

Indeed, I will and will let you know.