Help with this quesion

[#1]

Hi, anyone

Anyone can help me, i need to do the sum of sales but i have to do a comparison with the previous month, example, if i select september october and december 2009, i need another column in my simple table chart with the sum on June, july and august, any ideas will be appreciate

Regards

CArlos

[#2]

Hi Carlos,

please see the attached example and worksheet "Quarter".

Here you will find the expressions yoe need.

Good luck!

Rainer