"averaging" standard deviations

mc244

New Member
Hello,

I've been given the mean and standard deviation of many sets of the same measurement (bead size). So, I basically have a list of means and a list of corresponding standard deviations. I need to pool and analyze the data to figure out the overall distribution of bead size over these 100+ sets. Fortunately, each group has the same number of measurements, so they can be weighted equally.

Ideally, I would like to create an aggregate distribution curve for all of the data, but as I only have a list of 100+ means and SDs, I'm not sure how to do this in excel. Is it possible?

If I can't easily make a size distribution curve, at the very least I would like to (1) get a total mean (I am assuming since all groups are of equal size I can average the means), and then (2) get an "average" standard deviation. I can't figure out how to get an average standard deviation. Can anyone help with this?