Chemistry Question!?

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At a particular temperature, the equilibrium concentration of NH3 is found to be 0.544 M.
Given this information, determine the numerical value of K for this reaction, at this temperature.
(If you want to enter your answer in scientific notation, use the format as shown below:
2.5 x 10-3 = 2.5E-3)

K = ?
N2(g) + 3H2(g) ----> 2NH3(g)

The reaction is this Sorry!
This was the previous problem! In a given experiment, 1.84 moles of N2(g) and 4.52 moles of H2(g) were placed in a 3.61 L vessel. Complete the following table by entering numerical values in the Initial row and values containing the variable "x" in the Change and Equilibrium rows. Define x as the amount (mol/L) of N2 that reacts to reach equilibrium. Include signs in the Change column to indicate a gain or loss of concentration. (Omit units and spaces, use 3 sig. fig. and write concentration less than 1 as 0.###, not as .###. If nothing is present initally, enter 0 for the molarity.)
But i completed it already!