I have a large chunk of sales data with (some columns removed for clarity purposes):
Order Id, Order Date, Product, Amount, Product Price, Row total cost, Order total cost
A specific order can, as you may see, be divided over multiple rows - were order id, order date and order total is the same on each row. The "row total cost" contains the price for a specific amount of a specific product in the order.
It's not the best way to store data - I know...
Any ways. What I would like to do is to calculate the average sales value for each month. For example - total sales in sep 2012 is $1000, and in sep 2013 it's $500. The average sale for september would be 1000 + 500 / 2 = $750.
This I would like to present in a pivot table and pivot chart.
What I'm stuck with is an average sales value compared to the grand total (sep 2013 compared with all month of 2013 and 2012). I believe I need to group or filter my average calculation - but can't figure out how to do that.
Any help is much appreciated. Using Excel 2013.