Yes you definitely have a shot at a Top20 program. With strengths being your ethnicity and perspective (Iran is an extremely underrepresented country in US b-schools), your education in engineering (2.7 GPA is not good but your GMAT counter balances it plus b-schools know engineering grades are generally lower). Your weakness is going to be your work experience and your post MBA goals. It's a bit of a leap to go from being an English teacher to being a hedge fund manager, so how you communicate your plan to make this transition will be crucial. You have the intellect and education to make the jump but they will definitely question why you chose to go to engineering school to become and English teacher and why you have not made any attempts to work in finance industry. One thing b-schools hate is when they perceive applicants are using the degree as the "magic ticket" to get them out of a poorly chosen path and onto a better one. You will need to eliminate this potential concern by showing that your path was intentional and that you gained some valuable skills in your career to leverage going forward. One big things schools look for is what you bring to the table from your career experience that will be valuable for your classmates, so if you couch your experience with this in mind, you will be positioning yourself as best as possible with the adcom.
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Bryant Michaels
Admissions Consultant