As an alternative to Friend’s rule and Cowling’s rule, pediatricians sometimes use the formula

to estimate an appropriate drug dosage for a child whose surface area is S square meters, when the adult dosage of the drug is A milligrams (mg). In turn, the surface area of the child’s body is estimated by the formula

where W and H are, respectively, the child’s weight in kilograms (kg) and height in centimeters (cm).

a. The adult dosage for a certain drug is 250 mg. How much of the drug should be given to a child who is 91 cm tall and weighs 18 kg?

b. A drug is prescribed for two children, one of whom is twice as tall and twice as heavy as the other. Show that the larger child should receive approximately 2.22 times as much of the drug as the smaller child.

Transcribed Image Text:

C = SA 1.7