Comparing data of current week and last week while calculating sell-through

Anonymous — Fri, 22 Jun 2018 04:34:43 GMT

Hi all! I am calculating the sell through rate of a product.

Right now, I have weekly sales and inventory data.

The formula of the rate is the sales quantity divided by the inventory of the last week.

However, I don't know how to write the expression of the measures.

I have tried the following but it won't work:

SUM(Sales)/SUM({<[Date]={[Date]}-7>}Inventory)

Please help solve! Thanks in advance!!

p.s. This is the expected answer:

topic Comparing data of current week and last week while calculating sell-through in App Development