A ternary co-solvent system is to be comprised of water, glycerin, and 8% v/v ethanol, and has a target mixed dielectric constant of 65.5. Assuming x represents fwater, the following expression results:
Emix=65.5=80(x)+20(0.08)+46(0.92-x)
Based on this expression, the % v/v concentration of glycerin should be: