Picture this: I’d like to plot the trendline of (say) an election poll result over time. Aside from that one narrow line, I’d also like to plot a fat line in the background that shows how the range of the margin of error fluctuates over time, so I can point to instances where the thin line breaks out of the fat line’s range.
There are ways I can jury rig a solution, but they’re all frankly a PITA to work around. Is there a simple way, preferably in Excel?
Taking some inspiration from Edward Tufte’s favorite chart, if it means anything to you . . .