Hello MrShorty,

Thank you for your reply!

I actually solved the mean issues with the following website

http://www.buzzardsbay.org/geomean.htm#negative_values

However I am still trying to find an efficient way for the up/downside standard deviations. My workaround at the moment is to create a new row with that duplicates positive/negative values only, and calculate a STDEVA() from there. But there must be a better way...