Pediatric dose formulas generally fall into two families, ones that scale the adult dose by body weight and ones that scale it by age. Sorting these four options into those families answers the question directly.
- Clark's formula: Weight goes straight into the equation, either kilograms over 70 or pounds over 150, multiplied by the adult dose, placing it firmly in the weight-based family.
- Fried's formula: Built for infants, it uses age in months divided by 150 as the scaling factor, an age-based method suited to very young children.
- Young's formula: Uses age in years divided by age in years plus twelve, another age-based method, this one meant for slightly older children.
- Dilling's formula: Uses age in years divided by twenty, also an age-based method, generally applied to older children closer to adult dosing.
Three of the four formulas scale the dose by the child's age, leaving Clark's formula as the single weight-based method among them. The correct answer is Clark's formula.