Question

It is important to know the appropriate dose of ibuprofen for a child so that you are ready in the case of high fever. The dosing guidelines state that children should be given 8mg/kg. Determine the dose of ibuprofen needed for a 2 ½ year old weighing 28 pounds. Round your final answer to the nearest whole number and make sure to state your units to earn full credit! (Recall: 1 kg = 2.2 lb)

Answer 1

102 mg

Explanation:

First, find the weight, in kilograms, of a 2 ½ year old child weighing 28 pounds.

1 kg = 2.2 pounds

x kg = 28 pounds

Write a proportion

`(1)/(x)=(2.2)/(28)`

Cross multiply

`2.2x=28\\ \\22x=280\ [\text{Multiply by 10}]\\ \\x=(280)/(22)=(140)/(11)=12(8)/(11)\ kg`

Now, the dosing guidelines state that children should be given 8mg/kg. So,

8 mg - 1 kg

y mg -
`(140)/(11)\ kg`

Write a proportion

`(8)/(y)=(1)/((140)/(11))`

Cross multiply

`y=8\cdot (140)/(11)=(1,120)/(11)=101(9)/(11)\approx 102\ mg`

Answer 2

102 mg

Explanation:

Let's convert 28 pounds to kgs.

Since 1 kg = 2.2 pounds, we can find:

`(1Kg)/(2.2Pounds)=(xKg)/(28Pounds)\\1*28=2.2x\\28=2.2x\\x=(28)/(2.2)\\x=12.73`

So 28 pounds is 12.73 Kg

Since 8mg is given per kg, for 12.73 kg, the amount given should be:

12.73 * 8 = 101.84

Rounded to nearest whole number, that is, 102 mg