No doubt about it. Even with a GMAT of 640, you can get into doctoral programs in business, including some that are AACSB-accredited. It depends on what particular kind of university you're considering. Your strategy of getting a master's in accountacy is excellent. Also, even though your prior GMAT score is good enough, it would not hurt to take the GMAT again, especially since a high score can mean some good grants.
Richard S. Voss, Ph.D.
Chair, Graduate Business Programs
Troy University, Southeast Region
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