Monkeybone:

Your final calculation figures look fine to me - considering in the first forumula you are only mixing 98% of a gallon (69% + 10% + 18% + 1%) and in your second formula you are only mixing 90 % of a gallon (70% + 20%). If you add 2% of something to the first forumula and 10% of something to the second formula then you should calculate to 128 oz gallons.

Your mix percentages on the left side have to equal 100% or your final calculations cannot equal 128 oz (full gallon).

Dan