help: need to increase fill volumes

[seanb.]

I need to widen the fill volumes of a bottle fill weight {lower limit 43.5g - upper limit 46.1}. also when tested the drug inside may not be above 120% (high level) nor below 90% (low level) at the moment when tested I have an average high of 107.5% (1.6). I have average low of 99.3 (3.6) how do I calculate the new fill limits.

How do I aproach this problem?

Thank you for any help

Sean