The following data are for a liquid chromatographic column: column width 24.7 cm volume of the mobile phase, Vm 1.37 mL volume of the stationery phase, Vs 0.164 mL A chromatogram of a mixture of species A, B, C and D provided the following data: Calculate the retention factor for for species D. Retention Time, min Width of Peak Base (W), min Non Retained 3.1 - A 5.4 0.41 B 13.3 1.07 C 14.1 1.16 D 21.6 1.72