Right-click on your graph and choose to Create->Property Node and then find X-Scale->Offset And Multiplier->Multiplier.
You probably should have kept that in the original discussion.
There are also ways to avoid that property node:
Note that waveform graphs also accept clusters of (x0, dx, [Y]), and waveform datatypes, allowing you to define dx without any property node. Two simple alternatives would be the following: