Final answer:
To calculate the dosage of the medication required for a person who weighs 140lb, divide their weight by 80lb to find the number of 80lb intervals, and then multiply this number by the dosage for 80lb.
Step-by-step explanation:
To determine how many milligrams of the cold medication are required for a person who weighs 140lb, we can use the given dosage of 2mg for every 80lb of body weight.
First, we need to find the number of 80lb intervals in 140lb. 140/80 = 1.75. This means that the person weighs 1.75 times the dosage required for 80lb.
To find the dosage for the person who weighs 140lb, we can multiply the dosage for 80lb (2mg) by the number of intervals (1.75). 2mg x 1.75 = 3.5mg. Therefore, 3.5 milligrams of the medication are required for a person who weighs 140lb.