you should know what temperature you are expecting to get then from there:

take 3 measurements X, Y, and Z respectively

X+Y+Z

------ x 100%

Mean

Average diviation/ mean x 100%

What do you mean with

*average diviation*?

If I have the table:

--------------- gas volume (0.1)

Temperature (1) - trial 1 - trial 2 - trial 3

25 ----------- result 1 - result 2 - result 3 (or X, Y, Z) -> average

30 ----------- result 4 - result 5 - result 6 -> average

35 ----------- result 7 - result 8 - result 9 -> average

I want a table, which only shows the averages and the combined uncertainty.

By calculating the percentage uncertainty, I calculate the uncertainty for when I take the average?

(result 1 + result 2 + result 3) / 3 = average 1 (unc. ?)

Now I am not quite sure what you mean with

*(X+Y+Z)/mean*, because when you do that, you get the number of measurements taken and then multiply it by 100?

The table I would like to have:

------------------- gas volume (

**uncertainty ?**)

Temperature (1) --------------------------

25 ----------------- average 1

30 ----------------- average 2

35 ----------------- average 3