The top-rated answer here worked for me... sort of. I was trying to do exactly the same thing as the questioner except on a chart of horizontal bars, not a chart of vertical columns. I should have been able to accomplish this by:
- selecting "Format Axis" from the Y-axis
- in the pop-up menu, selecting both "Categories in reverse order" and "Horizontal axis crosses: At maximum category"
But this only changed the order in which the data appeared -- it didn't "flip" the values as desires.
The workaround: Convert the chart to a vertical column chart, make the "Categories in reverse order" and "Crosses: at maximum category" selections in the Format Axis pop-up, then convert back to a horizontal bar chart.