3. The following surface tension data has been adapted from work by L. J. Naylor, V. Bakatselou and J. B. Dressman (Pharm. Res. 10. 865-875, 1993). The experiment was carried out at 25C and the medium maintained at pH 5.5. The bile salt sodium taurocholate (NaTC) was used as the surfactant. Graphically determine the critical micellar concentration of NaTC in this system. NaTC (mm) 0.00 0.25 0.70 1.10 2.00 3.00 4.20 Surface tension (dynes/cm) 72.0 70.0 67.3 65.5 61.0 57.2 55.8 55.6 55.7 5.00 6.00