The conversion of glucose-6-phosphate to fructose-6-phosphate is catalyzed by an isomerase enzyme. Glucose-6-phosphate was mixed with the enzyme under standard conditions and the reaction was allowed to come to equilibrium. If the Keq' is 0.50 and the equilibrium [glucose-6-phosphate] is 1.33 M, what is the equilibrium [fructose-6-phosphate]?