Adding reference lines to a chart with primary and secondary axis

Good day all! New to the forum! I have a chart with sales data on one axis and inventory on a secondary axis. I have the average of each columns of data and want to add a reference line to each axis with it's average. I have added the averages to my data set, but it only adds the reference line to my primary axis. I actually began by manually inserting two lines to the chart (which seems asinine). They actually didn't print because they weren't actually on the chart, but rather just on the spreadsheet behind. So neither solution is working for me right now. Please help, thanks!

Ben

Using Excel 2003, I can see that your 'Avg Wrt Sales' has a legend and should show up on the graph, but the data is not on the chart.

When I create a new chart with your data (standard line chart), eveything seems to work OK. I do have to 'Right Click ' on the 'Total Cubes' and 'Avg Cubes' data lines, select 'Format Data Series' to put those items on the 'Secondary Y Axis'.

I hope this helps.

Lewis