# Simple Probability of an event

I have 1000 computers and 2 have failed with a specific code bug. They all are exposed to the bug, because they all have the same code running. Just using those numbers, is the probability of the failure event 2/1000 ?

• Why do you see the occurence of a bug as a random thing? If you rerun the code on all computers, will the same computers bug out? – Roland Jan 28 '14 at 12:08
• Yes, same code is running on all, so it is somewhat random; dependent on many variables, some of which can not be easily determined. – user38092 Jan 28 '14 at 22:50

What you are doing is to estimate the unknown p of the model by your empirical probablility $\hat p = \frac{2}{1000}$. This doesn't tell you the true value of p. Also, it doesn't tell you how good your estimation is, i.e. how close it is to the true value, but this kind of questions can be answered with the help of confidence intervals.