My data includes the cost of item over time, the item is clustered by vendor. I want to first calculate the standard deviation for each item, then average the standards deviation within each vendor.
Please see the screenshot for the data and table. I can calculate the std for each item, but I want to take AVG(3.5355 + 14.1421) as the variation for vendor1 and take AVG(14.1421+49.4974) as the variation for vendor2. I used the expression: Aggr(avg(Stdev(cost)),vendor), but it didn't work.
Also, if I don't want to add item as a dimension, I just want to include vendor as the dimension and the average std for the vendor, is there a way to achieve this?
