ANSWER
geometric mean of n numbers
= ( product of n numbers)^n
=>where n belongs to set of positive integers
we require for n = 2
Let us take numbers 4 and 8
so, geometric mean between 4 and 8
given by, => ( 4×8)^(1/2)
=> ( 2 × 4 )^(1/2 ×2)
=> 2×4
=> 8
hope it helps you