How to set changing upper/lower limit lines on graph builder

[#1]

Hello, 

I have a simple Y vs X graph that the upper limit and lower limit are changing at different X values. Does anyone know how to do this on Graph Builder? or if there's a better way to do it?

Thanks,

Gary

[#2]

Can you provide an example with Fit Y by X that you want to reproduce in Graph Builder?  I'm not sure what you're referring to.

[#3]

I'd like to produce something like attached with the two red lines being the reference lines changing against X.

[#4]

This looks like an UWMA control chart.  You can get something like this in Graph Builder if you make the limits of X another series along with the actual data.  Here's what the result looks like.

I made the series for the upper and lower limits and simulated data, then I stacked them to get them into a single column with labels.  See the attached data tables.

[#5]

Good idea! this should work for me! thanks!