I want to know how many ounces of fertilizer to mix per gallon of stock solution to be injected at a certain injector ratio to get a certain concentration of nitrogen.
I have the fertilizer label which gives an example of how many ounces per gallon for some concentration of nitrogen at some injector setting.

What is the desired nitrogen concentration? ppm N

From the label, to achieve a concentration of ppm N at an injector ratio of 1 : , mix ounces of fertilizer per gallon of stock solution.

What injector ratio will be used? 1 :