I have data for the temperature of a flame at a given height above the burner. The temperature fluctuates quite a bit (see figure), but there is definitely an "average" value that it tends to fluctuate around. Is there a good way to find this value? I'm using excel for data analysis.
If that's your data, well, then that is it. Dont try to manipulate your data or methods to get what you want to see. Just take the average of each burner.
One other thing you could do is to look for the possible sources of variability on your measurements and try to reduce that variability to the minimum. Or you could just take measurements for a longer time, so you got more points to average, it should look less random.