First time trying to use M in power query... what I have is this table

I need to create two columns that per each row (combination of CD_Loja x CD_Produto )returns me the sum of QT_VENDA for that combination divided by the # of days in the past 3 months. The other column is pretty much the same but with the sum of VL_VENDA_LIQ Instead.
I.e: For the first row I want to sum up all QT_VENDA that matches CD_PRODUTO =1001930 AND CD_LOJA = 151 in the past 3 months (the DATE column has daily data) and divide it by the number of days in those 3 months.
Is there a way to do so ? And how do I go about this ?
Thanks in advance.