Adjusting something by percent weight

[dwd2012]

I'm having trouble trying to figure out how to adjust a mixture of ingredients when one the ingredients goes over the target weight. So say the target weights are: 284.321, 356.883, 1298.667, 1180.138, which by % weight is 9.113%, 11.439%, 37.825%, and 41.624%? What if when I added 284.321 units, I instead added 300 units. How would I adjust everything else so the ratio is still the same. I have tried doing a percent change, x-y/x and increasing the others by the same but I'm not getting those same % weight values-very close, but not identical.

Could someone elaborate on a type of formula that would always give me those % weights no matter what the initial weight is?

Thanks

 

[pappus]

I'm having trouble trying to figure out how to adjust a mixture of ingredients when one the ingredients goes over the target weight. So say the target weights are: 284.321, 356.883, 1298.667, 1180.138, which by % weight is 9.113%, 11.439%, 37.825%, and 41.624%? What if when I added 284.321 units, I instead added 300 units. How would I adjust everything else so the ratio is still the same. I have tried doing a percent change, x-y/x and increasing the others by the same but I'm not getting those same % weight values-very close, but not identical.

Could someone elaborate on a type of formula that would always give me those % weights no matter what the initial weight is?

Thanks

1. Your percentages doesn't add up to 100%

2. If (and only if) 300 wu (weight units) corresponds to 9.113% you are able to determine the total amount of the complete mixture. Let T denotes the value of the total amount then you know:

\(\displaystyle \displaystyle{\frac{300\ wu}{T} = 9.113\% = 0.09113}\)

Calculate T.

3. Now use the new value of T and your percentages to determine the actual values of the ingredients.