If A, G and H are A.M, G.M and H.M. of any two given positive numbers, then find the relation between A, G and $\mathrm{H}$.
(1) $\mathrm{A}^{2}=\mathrm{GH}$
(2) $\mathrm{G}^{2}=\mathrm{AH}$
(3) $\mathrm{H}^{2}=\mathrm{AG}$
(4) $\mathrm{G}^{3}=\mathrm{A}^{2} \mathrm{H}$