Step 1: Understanding the Concept:
Pediatric dose formulas scale the adult dose down for a child, and they do this using either the child's age or the child's body weight as the scaling factor.
Step 2: Key Concept or Approach:
Sort the four named formulas by which variable, age or weight, sits in their calculation, since that alone answers the question.
Step 3: Detailed Explanation:
Young's formula uses age in years divided by age plus 12, so it is age based.
Fried's formula uses age in months divided by 150, so it is also age based, aimed at infants.
Dilling's formula uses age in years divided by 20, again purely age based.
Clark's formula is different: it uses the child's weight in pounds divided by 150, multiplied by the adult dose, which makes body weight the deciding factor.
Step 4: Final Answer:
Clark's formula is the one that calculates the child's dose based on body weight.