Examine the data given below in the table on purification of a protein X. Step Volume (mL) Protein Concentration (mg mL -1) Enzyme Activity (unit mL -1 ) Crude cell-free extract 500 12.0 5.0 Ammonium sulfate precipitation 125 3.0 11.0 Ion-exchange chromatography 10 9.0 75.0 The yield percent and purification factor, respectively, at the end of the experiment will be approximately