A homogeneous ideal gaseous reaction $\mathrm{AB}_{2(\mathrm{~g})} \rightleftharpoons \mathrm{A}_{(\mathrm{g})}+2 \mathrm{~B}_{(\mathrm{g})}$ is carried out in a 25 litre flask at $27^{\circ} \mathrm{C}$. The initial amount of $A B_2$ was 1 mole and the equilibrium pressure was 1.9 atm . The value of $\mathrm{K}_{\mathrm{P}}$ is $\mathrm{x} \times 10^{-2}$. The value of x is $\_\_\_\_$ .