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I've run simulations, tens of thousands of them at a time, over and over as we developed chips. In one project I noticed that I could predict the final result after only a small number of results were in which allowed me to halt the rest of the simulations, or make advance preparations for the final result.

I looked it up at the time and, indeed, there is an equation where if you want the pass rate of a "large" population to within a given accuracy, it will give you the minimum sample size to use.

Every time we run that pass_rate expression we get a different value. It is random. We need to run that pass_rate calculation many times to get an idea of what the likely pass_rate would be when using the given sample size:

I have learnt that the question to ask is not how many times the sample pass rate was the population pass rate, but to define an acceptable margin of error, (say 5%) and say we want to be confident that pass rates be within that margin a certain percentage of the time

So for a sample size of 123 we could expect the pass rate of the sample to be within 5% of the actual pass rate of the population, 0.5 or 50%, onlr o.4 or 40% of the time!

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