Comment by simcop2387

I believe that's the geometric mean he's referring to.

  (a*b)^1/2 # geometric mean, square root of the product of the two numbers
  (10^5 * 10^6)^(1/2) # substitute in for 10^5 and 10^6, the limits of the six-figure range
  (10^(5+6))^(1/2) # simplify inner product
  (10^11)^(1/2) # more simplify
  10^(11 * 1/2) # move the 1/2 in, and ...
  10^(11/2) # simplify
  10^5.5 # and finally you get the same result

The geometric mean always struct me as an interesting idea in mathematics