From: Stan Hilliard
Date: 7/21/2005
Time: 12:41:50 PM
A purely random procedure would select 125 units randomly from the 720,000 regardless of what box they are in.
I do not know of any method to determine the number of boxes based on statistics. However I have seen this rule of thumb that seems to be reasonable.
Sqrt(600)=25 boxes randomly or at a constant interval.
125/25=5 units selected randomly from each selected box.