Hello: I am attempting to average columns that have headings of Inventory. My spreadsheet consists of the following column headings: Inventory, Sales, Purchases. Each week I run a query that posts Inventory, Sales and Purchases for 450 Inventory items.How can I average the column heading of Inventory for the 52 weeks across these column headings. I tried using average(if(a1:a52 ="Inventory", a2:a52) but it doesn't work. Any help would be appreciated.

Thank you

Gene Haines