I am trying to insert vertical lines on a histogram to represent the mean
average and the control limits.
The problem I'm having is that the line show up in the wrong place because
they don't use the same x axis as the histogram uses. The vertical lines use
a secondary axis that isn't on the same scale as the primary axis that the
histogram is on. I can manually adjust the scale of the secondary axis, but
the data in the histogram is always changing and the scale of the histogram
is always changing, so I would have to change the scale of the secondary axis
each time the scale of the primary axis changes.
Is there any way to either plot the vertical lines on the primary X axis
instead of the secondary X axis, or to make the scales automatically match
each other (or any other solution I have overlooked.)
Thank you very much!

Adam