Formulas

Cowling's rule.  Cowling's rule is another function for determining the child's dosage of a drug. For this rule, the formula

expresses the child's dosage d as a function of the adult dosage D and the child's age a.

a)	If a doctor prescribes 1000 milligrams of acetaminophen for an adult, then how many milligrams would she prescribe for an eight-year-old child using Cowling's rule?
b)	If a doctor uses Cowling's rule to prescribe 200 milligrams of a drug to a child when she would prescribe 600 milligrams to an adult, then how old is the child?

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