Reference Lines do not appear

[#1]

I am trying to add reference lines to my x-axis in graph builder.  I can add the to y-axis just fine.  But when I try to add in the x-axis settings, they are typed in, but do not show up on the graph after selecting ok.  Am I missing something here?

[#2 · Accepted solution]

My first guess is that the X column is a character column, not a numeric.  If that is the case, the actual values that have to be referenced are 1 to 6

[#3]

Thanks. It was a numeric column, but set to ordinal. A switch to continuous allowed the lines to appear.