If an animal weighs 10 lbs. and requires 3 mL of medication, how much would a 40 lb. animal need if the dosage is proportional?

To determine the medication dosage for a 40 lb. animal based on the proportionality established with a 10 lb. animal, you can set up a simple proportion. If a 10 lb. animal requires 3 mL of medication, then for a 40 lb. animal, which is four times heavier, the dosage would also need to increase proportionately.

Using the relationship:

10 lbs = 3 mL
40 lbs = X mL

Since 40 lbs is four times 10 lbs, you can multiply the dosage of the smaller animal (3 mL) by 4 to find out how much the 40 lb. animal would need:

3 mL x 4 = 12 mL

Thus, a 40 lb. animal would require 12 mL of medication to ensure the dosage is proportional. This calculation confirms that the appropriate answer is indeed 12 mL.