Here's what I got.
You're dealing with a chemical reaction that involves gases, so you can write two equilibrium constants, one that uses the equilibrium concentrations of the species,
In both cases, you're going to be using the ratio that exists between the products and the reactants.
For equilibrium concentrations, you will have
#K_c = (["CO"] * ["H"_2]^3)/(["CH"_4] * ["H"_2"O"])#
Notice that the equilibrium concentration of each species is raised to the power of the stoichiometric coefficient that the species has in the balanced chemical equation, i.e.
For equilibrium partial pressures, you will have
#K_p = (("CO") * ("H"_2)^3)/(("CH"_4) * ("H"_2"O"))#
This time. the partial pressure of each species is raised to the stoichiometric coefficient that the species has in the balanced chemical equation.