The half-maximal velocity of an enzyme catalyzed reaction was found at a substrate concentration of \(0.5 \times 10^{-6} \, \text{M}\). This enzyme follows Michaelis-Menten kinetics. In the presence of a competitive inhibitor, the half-maximal velocity was found at a substrate concentration of \(1.5 \times 10^{-6} \, \text{M}\). Given that the enzyme-inhibitor pair has a dissociation constant of \(2 \times 10^{-7} \, \text{M}\), the concentration of the competitive inhibitor in \(\mu M\), rounded off to one place of decimal, was ______.