This is a little hard to describe.
I have an x-y chart using two columns of data separated by one column. The chart
uses a continuous burgundy line to display the data. I then Modify Data Range...
and add in two more columns of Y data. Now use one column of data for X axis and
three columns for Y-data. As expected I now have three lines.
I change the first new line to use ultrafine dashed and then change the second
new line to use fine dashed and the original line becomes dashed in the display.
In the properties box it is still marked as continuous. If I change the Style,
it doesn't matter what I do it still remains dashed.