Running sum

Source Result
Part Number Qtr Qty Price Part Number Qtr Qty Price Running Sum
ABC123 QTR 1
100
3
ABC123 QTR 1
100
3
3
ABC123 QTR 2
150
3
ABC123 QTR 2
150
3
6
ABC123 QTR 3
200
1
ABC123 QTR 3
200
1
7
ABC123 QTR 4
250
3
ABC123 QTR 4
250
3
10
ABC124 QTR 1
200
2
ABC124 QTR 1
200
2
12
ABC124 QTR 2
200
1
ABC124 QTR 2
200
1
13
ABC124 QTR 3
200
1
ABC124 QTR 3
200
1
14
ABC124 QTR 4
200
5
ABC124 QTR 4
200
5
19
ABC125 QTR 1
150
3
ABC125 QTR 1
150
3
22
ABC125 QTR 2
150
3
ABC125 QTR 2
150
3
25
ABC125 QTR 3
100
3
ABC125 QTR 3
100
3
28
ABC125 QTR 4
100
3
ABC125 QTR 4
100
3
31


Code:
let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    TableType = Value.Type(Table.AddColumn(Source, "Running Sum", each null, type number)),
    Cumulative = List.Skip(List.Accumulate(Source[Price], {0}, (state, current) => state & {List.Last(state) + current})),
    RT = Table.FromColumns(Table.ToColumns(Source)&{Cumulative},TableType)
in
    RT