Natural gas $left(mathrm{CH}_{4} ight)$ is flowing in a 6 in. sch 40 pipeline at 50 psig and

Natural gas $\left(\mathrm{CH}_{4}\right)$ is flowing in a 6 in. sch 40 pipeline at 50 psig and $80^{\circ} \mathrm{F}$. A 3 in. diameter orifice is installed in the line, which reads a pressure drop of $20 \mathrm{in} . \mathrm{H}_{2} \mathrm{O}$. What is the gas flow rate, in $\mathrm{lb}_{\mathrm{m}} / \mathrm{h}$ and $\mathrm{scfm}$ ?