How can you calculate the pounds of active ingredient of herbicide used?

The formula to calculate the pounds of active ingredient of herbicide used is rooted in understanding how volume, concentration, and the percentage of active ingredient relate to each other. The correct approach involves converting units appropriately while ensuring the active ingredient's impact is accurately represented.

In option A, the calculation begins with the water volume in acre-feet, which is a standard unit for measuring large water bodies. By multiplying this volume by the concentration in parts per million (ppm), you derive the total concentration of the herbicide in the water. The factor of 2.7 is a conversion factor that allows for the appropriate transition from gallons to pounds when necessary, as it accounts for the specific density of the substance being measured.

Furthermore, multiplying by the percent active ingredient and then dividing by 100 converts the percentage into a usable decimal form, giving the exact weight of the active ingredient in pounds. Each part of this calculation ensures that the final result accurately reflects the total application of the active ingredient based on the given conditions.

The importance of the selected formula lies in its comprehensive integration of all necessary elements—volume, concentration, and active ingredient percentage—allowing for precise and applicable results in aquatic pest management situations.