If one geometric mean G and two arithemtic means p and q be inserted between two numbers, then G2 is equal to:
(2p-q) (2q-p)
Let numbers be a & b
⟹ a,g,b in G.P. and a, p, q, b in A.P.
⟹ g2 = ab & p -a=q-p=b-q
we get a = 2p - q & b=2q-p
so g2 = (2p - q) (2q - p)