# Standard Error Analysis.

1. Apr 2, 2010

### hhhmortal

1. The problem statement, all variables and given/known data

Hi, I have this question that is bothering me. If I have a large set of data, each with its unique error uncertainty. How do I get the average error uncertainty from all the data points? Do I simply use the equation below:

(∆ Z) ² = (∆A)² + (∆B)²

And divide the error obtained from this by the total number of errors combined?

Thanks.

2. Apr 2, 2010

### rock.freak667

As in you want to find the standard deviation for a sample?

$$s^2=\frac{\sum_{i=0} ^N (x_i -\bar{x})^2}{N-1}$$

3. Apr 6, 2010

### hhhmortal

I want to find the average error of the sample, given that every value has its own different error uncertainty.

4. Apr 6, 2010

### Stonebridge

The average error is just the average of the errors.
Add all the errors together ignoring the minus signs, and divide by the number of values.
Is that waht you mean?
http://www.rit.edu/cos/uphysics/uncertainties/Uncertaintiespart1.html#estimate [Broken]

Last edited by a moderator: May 4, 2017