Using the West nomogram scale, the nurse needs to calculate the safe dosage of a medication for a child. The child is 50 inches tall and weighs 76 lb. The normal dosage of the medication for an adult is 300 mg. Which of the following is the correct way to use the West nomogram scale?

Use the “shortcut” scale because this child is average. This will show the nurse the percentage of the adult dosage appropriate for this child. Use this percentage to calculate the dosage.

Locate the child’s height and weight on the nomogram. Use a straight edge to align these numbers with the scale indicating percentage of adult dosage and multiply the adult dosage by this number.

Locate the child’s height and weight on the scale, multiply those two numbers, and divide the adult dosage by the resulting number.

Use the scale to locate the child’s height and weight. Use a straight edge to align these numbers with the scale indicating the surface area, divide that by the average adult body surface area, and multiply the resulting number by the adult dose.