Experimentation Source 4 (Source)
From SWGANH Wiki
Reference Documentation - Experimentation
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Your assumption is correct, all experimentation in SWG uses this formula :
Stat = [Base value at 0% experimentation] + ([Increase/%] x [Experimental Percentage])
For example : X-Wing : Mass = 97500 + (5000 x E) with E = Experimental Percentage
The initial and maximum Experimental Percentage depend on the resource stats, resource amounts and the applicable stat percentages for the item youre making. These values make up the Weighted Resource Value and determine the initial and maximum experimental percentage this way :
Initial EP = 0.00000015 x WRV^2 + 0.00015 x WRV
Maximum EP = 0.001 x WRV