UVA Math vs Econ and other questions

Hello,

I was recently accepted to UVA as a second year transfer, and I am interested In IB. I was accepted as a Math Major, but I am not sure how relevant math would be. Mcintire is out of the question because there are too many prerequisites for me to complete in a year. I figured being in the CAS school, Math or Econ would the best majors. Which would be better, a slightly higher GPA in Econ, or a slightly lower one in Math? Also, what courses should i take for better finance knowledge for recruitment this year? In addition, would the rosenbaum and pearl book be able to catch me up to speed alone?

Sorry for all the questions, just trying to cover all bases.