The following liquid phase parallel reactions are carried out in a plug flow reactor: (1) A + S --> 0.3 D, where -TA, reaction1 = K CA 2.0 CS 1.2 (2) A + S --> 0.5 U, where -TA, reaction2 = K2 CACS0.5 The desired compound is D, and the numerical value of k is 0.9 * the numerical value of k2, and both rate constants are in the mol, L, min units system. If the inlet concentrations of A and S are, respectively, 5.52 and 2.39 mol L-1. What is the instantaneous selectivity of D over U if the conversion of the limiting reactant is 0.75? Express your answer to one decimal place.