Question

an infant weighs 16 pounds and 8 ounces and needs a dosage of 80mg/kg. how many milligrams of this medicine do you need to give to the infant? use \1 pound: 16 ounces” and \1 kg: 2.2 pounds\.

Explanation:

Step1: Convert pounds and ounces to pounds

Since \(1\) pound \( = 16\) ounces, then \(8\) ounces \(=\frac{8}{16}=0.5\) pounds. So the infant's weight is \(16 + 0.5=16.5\) pounds.

Step2: Convert pounds to kilograms

Given \(1\) kg \( = 2.2\) pounds. Let \(x\) be the weight in kilograms. Then \(x=\frac{16.5}{2.2}\) kg.

$$x=\frac{16.5}{2.2}=\frac{165}{22}=\frac{15}{2} = 7.5$$

Step3: Calculate the dosage

The dosage is \(80\) mg/kg. For a \(7.5\) - kg infant, the dosage \(y\) (in mg) is \(y = 80\times7.5\)

$$y=80\times7.5=(8\times10)\times(7.5)=8\times75 = 600$$

Answer:

\(600\) milligrams