Adding a horizontal line to a chart that already has 2 axes?

[Nakia6]

I have a chart that has 2 axes with different values (left axis 0-100%, right axis 0-6). How can I create a threshold line (horizontal line) at the 1.5 mark on the right axis?

Thanks!

[Palmetto]

The quick easy answer is: create a dummy series all with same value and plot this.

More help here: John Peltier Charts

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