Assume we have a data source with this fields : Product / Qty
1- Make a combo chart with
- Dimension -> Product
- Measure -> Sum(Qty)
- Measure -> Accumulation % formula : RangeSum(Above(Sum(Qty), 0, RowNo())) / Sum(TOTAL Qty)
- Measure -> 80 % line formula : 0.8
Set the Accumulation % and the 80% line as Line charts on the secondary axis with a "# ##0%" number format.
2- Sort by Product (decrease) with a formula : Sum(Qty)