Hi,

I have a dataset that looks like this but with 800,00 rows

full date month year postcode category time (in seconds) area
01/01/2010 1 1 CB1 Red 1 654 East of England
02/01/2010 1 1 CB1 Red 2 351 East of England
04/01/2010 1 1 CB1 Red 1 903 East of England

I want to calculate the average time per each postcode but, as there are some outliers, I need the trimmed mean. I know how to use the =TRIMMEAN formula, but I don't know how to group per postcode and then calculate the trimmed mean. Like in a pivot table.

I would also need to add some more levels of complexity, like calculating the trimmed mean for a specific postcode in a specific month. But I guess that if I solve the previous problem, this will be easy.

Any ideas?

Thanks!