Ok so when i take and do what you say i get:
Jeweler A: 0.863g = 0.7 , 0.869g = 1.3, 0.859g = 0.3
These decimals divided by 3 = 2.6
The Percentages are: 99.1%, 98.5%, 99.6% and divided by 3 = 230.8
I also, got an average of 99% for jeweler A...
Jeweler B: 0.875g =1.9, 0.834g = -2.2, 0.858g = 0.2
These decimals divided by three = 4.3
The Percentages i got were: 97.8%, 102.6%, 99.7% = 233.6
I also, got an average of 100% for jeweler B.
So i think that Jeweler A is more Accurate and Jeweler B is more Precise...
i went out of my way spit balling any and every possibly answer... is there an easier way?