Weighted Average Price

Hi,I have a data that has as attributes such as unit cost in that week and order size.I want to calculate unit cost of this product in my inventory using weighted average of prices(which weights are order sizes of that week)My data goes like:

09/12/2022 

Order Size:50000 KG Unit Cost That week:1.25 USD

09/23/2022

Order Size 25000 KG Unit Cost that week:1.015USD

I want my unit cost calculated like this for the day that report is seen.For this formula I want to use the data that are previous from today.I appreciate all the help.Thanks.