A mixture of compound (1) +(2) was studied at T=85C. The vapor pressures (mmHg) are given below. The activity coefficients measured at x1=0.34 are y1=3.73 and y2=1.47. What value do ou determine for A12 from the one-parameter Margules model? Compound Psat (mmHg) (1) 813 (2) 566