[tex]\bf \cfrac{x}{\textit{geometric mean}}=\cfrac{\textit{geometric mean}}{y}\implies \cfrac{x}{\sqrt{12}}=\cfrac{\sqrt{12}}{\sqrt{3}}\implies \cfrac{x}{\sqrt{12}}=\cfrac{\sqrt{4\cdot 3}}{\sqrt{3}} \\\\\\ \cfrac{x}{\sqrt{12}}=\cfrac{\sqrt{4}\sqrt{3}}{\sqrt{3}}\implies \cfrac{x}{\sqrt{12}}=\sqrt{4}\implies \cfrac{x}{\sqrt{12}}=2\implies x = 2\sqrt{12} \\\\\\ x = 2\sqrt{4}\sqrt{3}\implies x=2\cdot 2\sqrt{3}\implies x=4\sqrt{3}[/tex]
