Weighted Moving Average

Weighted Moving Average

Hello.

Personal, my doubt is how to calculate the weighted moving average, in Power Bi, the problem is when I have to calculate the cost of the unit sold, 
multiplying by the average cost, and deducting this value from the Total.

Link with template file:https://drive.google.com/drive/folders/1F4X244y3NXB-hnM8rOuqE1UMLVU_3msC?usp=sharing
Example:

Initial = 100 Units of Product X, at the cost of R$ 500.00 per batch

Acquisition of 200 Units of Product X, at the cost of R$ 1,150.00 per lot

The average cost of Product X will be:

BRL 500.00 + BRL 1,150.00 divided by (100 + 200) units

= BRL 1,650.00: 300

= BRL 5.50 per unit

In the effective sequence to a write-off of -120 units

= 120 multiplied at the cost of R$ 5.50 = -660

Accumulated cost goes from R$ 1650.00 - 660 = 990 and the Total of 300 units - 120 = 180, maintaining the average cost, until a new acquisition.


In the example below, where it is 7.19 the correct is 5.81, which would be R$ 1650.00 - 660.00 +1800 = 5.81, if there is no sale Works perfectly.