Weighted averages in Power Query

[Stemar_Aubert]

Hi,

I have a set of data as follow.

LocalString	Units	Value	Sum
America	25	10	250
Australia	3	50	150
America	89	20	1780

And so on.

Before, I would group and take the average value. But the introduction of Units means I need a variant of Sumproduct() formula.

Is there a way, using PowerQuery only, to perform the following operation ?

For each America = (250+1780)/(25+89)

Thanks

[dax]

Hi Sauber,

You could try below M code to see whether it work or not

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcsxNLcpMTlTSUTIyBRKGBmCWgVKsDlCutLikKDEnEyRrDMSmIElDmCRco4UlSA9YztwCKBkLAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [LocalString = _t, Units = _t, Value = _t, Sum = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"LocalString", type text}, {"Units", Int64.Type}, {"Value", Int64.Type}, {"Sum", Int64.Type}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"LocalString"}, {{"total  sum ", each List.Sum([Sum]), type number}, {"total unit", each List.Sum([Units]), type number}, {"all", each _, type table [LocalString=text, Units=number, Value=number, Sum=number]}}),
    #"Added Custom" = Table.AddColumn(#"Grouped Rows", "Custom", each [#"total  sum "]/[total unit]),
    #"Expanded all" = Table.ExpandTableColumn(#"Added Custom", "all", {"Units", "Value", "Sum"}, {"all.Units", "all.Value", "all.Sum"}),
    #"Removed Columns" = Table.RemoveColumns(#"Expanded all",{"total  sum ", "total unit"})
in
    #"Removed Columns"

Best Regards,
Zoe Zhi

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[Anonymous · Accepted solution]

The code below should do the trick. Just adapt your List.Average to List.Sum([Sum])/List.Sum([Units]).

= Table.Group(Source, {"LocalString"}, {{"Sum", each List.Sum([Sum])/List.Sum([Units]), type number}})

[Stemar_Aubert]

@Anonymous Thanks, that worked perfectly !