Tough question! Frankly, I suspect different admissions officers would react differently to your score. The 50%ile is certainly marginal for the schools you are targeting, but the overall 700 is great.

At this point I would think twice about retaking the exam unless you have identified a key issue that is holding down your math score. Unless you have found something in your approach that needs changing, the score is unlikely to improve dramatically. Schools do claim to pay attention to the highest score. In your case, that would have them looking at the 68 %ile which should not be a major issue. You should take care in your essays to substantiate your quantitative ability by referencing undergraduate quantitative work or business quant skills. Did you take statistics courses in support of your psych degree? Do you have significant analytical responsibilities in your job. By all means emphasize those through your essays and your references.

Your work background should be an advantage. Many applicants come from horizontal organizations such as consulting firms in which they do not oversee the work of others and in which they interact largely with highly-educated peers. Your experience managing a large group of hourly employees in a hands-on environment should make you a strong classroom contributor. A seasoned admissions consultant can help you focus on strengths and downplay weaknesses in your application.

Your undergraduate grades in a double major should also be impressive. (I live in St. Louis and know the quality of the program at Wash U.) Do you have plans to use your Spanish for international business? If you are targeting consulting in your essays,. be specific. I am very leery of people who simply say they want to consult, Consultants consult about "something". You need expertise in a field before you can jump in and tell management what to do. Too many aspiring consultants come across as being focused on the "glamour" and money.

Good luck,