An analyst is to determine the molarity of a NaOH solution. Three aliquots of standard KHP are weighed out: 0.3192 g, 0.4790 g, and 0.3938 g. These three aliquots were titrated using a NaOH solution and required 15.76 mL, 23.72 ml, and 18.86 ml, respectively. From these data calculate the average molarity of the NaOH solution