Answer:
12.75
Explanation:
The computation of the geometric mean of sqrt 77 and sqrt 343 is given below:
As we know that
Geometric mean =

where
a is the first number =

And, the b is the second number =

Now first we have to convert into a number
For a it, is = 8.78
And, for b, it is = 18.52
Now the geometric mean is

= 12.75