Also doable with system.dataset.map from my Ignition Extensions module.
Or you could get fancy and use a custom tag history aggregate:
https://docs.inductiveautomation.com/display/DOC81/Custom+Tag+History+Aggregates
It would probably be best to fix this data at the source, though. If these tag values should be 3x higher...why not enable tag scaling on the root tag, so you don't have to manually adjust history down the road?