Geometric Mean

Something that plagues many geometry students is geometric mean. To be perfectly honest, there are few real life applications for this, but here we go:

Geometric Mean of Two Numbers:
If a question states something such as:

       Find the geometric mean of 75 and 10.

This is how you would write it out:

 x  = 10 
75     x

To solve, you would first cross multiply, or multiply diagonally.

x² = 750

Did you follow?
Now we are going to do the square root of both sides in order to get 'x' by itself:

x = 27.4 (Rounded to tenth)

If I was confusing, which I often am, comment, and I will attempt to clarify!