Scroll probability formula

Anyways, definitions:

Statistics: the concept that you will, on average, get at least 1 item with 10 10% scrolls working on it after each 10^10 tries (expected value). That's a prediction made on statistics, it doesn't predict whether the next scroll will work or not, just that after a sufficient ammount of tries things tend to the expected value.
http://en.wikipedia.org/wiki/Expected_value

Quite right; and you will use statistics along with the collected data (i.e. ur scrolled result: success/ fail; on which number of slot/ slot remaining/ type of scoll% and etc.) to run a "simulation" to get it (future expected value). This of course requires a simulation program. And like I've said; with a given dataset and formulas; you're all set to go. And here's the example that I've given from my previous post. (URL: http://www.oracle.com/us/products/middle...index.html). Simulation is the computerize-end of using statistic, and that is why statistics is useful, otherwise, it'll just be a bunch of jargon numbers.