I want to know what formula can I use to get an average (total?) error. What I did was try a method on 10 different samples a single time (obtaining 10 values), and then I tried an alternative method on those 10 samples (obtaining 10 new values). I then compared each of the values I obtained between corresponding samples (with the percentage error formula) and obtained 10 values which I considered the errors (I want to highlight that I did not perform repeated tests to obtain each of the errors of the method, it was single test for each method on each sample). So if I have ten error values which range from say -5% to 6% and I want to know what the average range of error is obtained form those values what formula do I use? I am assuming that saying my error is from -5% to 6% is wrong so I want to know if there is a way to convert those values into something like +/-4%, if it is even possible because maybe there is no formula for that? I was thinking maybe standard deviation or standard error, but I think those are only used when comparing means, which is not my case.