YTD Weighted Average

Hi,

I have data in a table which i need to calculate a dynamic weighted avergage YTD calculation in a matrix table.

the GL account code:

100359009100 - Is Ore Mined 

100359009103 - Is Ore Mined Grade

The data as you can see appears in the same collumn which is also mixed with financials and other physical amounts.

In excel i would just do a sumproduct(Ore Mined Grade:Ore Mined)/Total Ore Mined

I am just really stuck to how i write a formula as i want the formula to be able to calculate the next row which is YTD Ore Mined PPM which is also a weighted average of Ore Mined.

Please see pictures of the data. The picture of the data only relates to budget 

The 2 matrix tables are currently just doing a YTD sum calculation with date filters which is just adding Mined Grade and PPM which is not the result needed.

Any suggestions would be great