For a project, I am trying to estimate the absorption curve of a certain plant species. Due to the variability within the species, I have taken the average of several measurements.
In the figure below, the blue curves represent 3 separate measurements, and the red curve is their average.
I want to shade an area around the resulting red curve as a kind of error bound to represent the observed variability. What quantity do I need to consider here?
The Attempt at a Solution
Should I simply shade the area from the lowest to the highest recorded value? Or is there some statistical parameter that I could use instead?
In reality, I have taken much more measurements than the three curves shown above. I would like to know the most appropriate way to represent the magnitude of the error bars.
Any suggestions would be greatly appreciated.