At a given temperature, 1.7 mole of SO2 (g) and 1.7 mole of O2 (g) are added to a 1.00-L container and react until the equilibrium below is achieved. At equilibrium, the container has 0.73 moles of SO3 (g). What is K, for the following reaction?

2 SO2 (g) + O2 (g) 2 2 SO3 (g)

Express your answer using at least two significant figures. Do not use scientific notation.