Convert 126 lbs. to kg.
a. 60 kg
b. 300 kg
c. 57.3 kg
d. 277.2 kg
The Correct Answer and Explanation is:
To convert 126 pounds (lbs) to kilograms (kg), use the standard conversion factor:
1 pound (lb) = 0.4536 kilograms (kg)
Step-by-Step Calculation:
$$
126 \, \text{lbs} \times 0.4536 \, \left( \frac{\text{kg}}{\text{lb}} \right) = 57.1536 \, \text{kg}
$$
Rounded to one decimal place:
$$
\boxed{57.2 \, \text{kg}}
$$
The closest option to this is:
c. 57.3 kg
Detailed Explanation (300 words):
In clinical and scientific contexts, it is often necessary to convert body weight from pounds to kilograms because kilograms are the standard unit of mass used in most countries and in medical dosage calculations. The conversion factor between pounds and kilograms is based on the fact that 1 pound equals approximately 0.4536 kilograms.
To convert 126 pounds to kilograms, you multiply 126 by 0.4536. This results in approximately 57.1536 kilograms. Rounding this to one decimal place, you get 57.2 kg. However, multiple-choice options may include small variations due to rounding. In this case, the closest correct answer is 57.3 kg.
Let’s examine the other choices to confirm:
- a. 60 kg is too high. 60 kg would be the result of about 132 lbs.
- b. 300 kg is extremely high — that would be over 660 lbs, which is not a reasonable match.
- c. 57.3 kg is nearly exact and matches the calculation closely after rounding.
- d. 277.2 kg is also much too high. This would correspond to over 600 lbs.
Therefore, only choice c fits the correct conversion.
Understanding this conversion is crucial for health professionals. For example, medication dosages for many drugs are calculated per kilogram of body weight. Giving an incorrect dose due to a conversion error could lead to underdosing or overdosing, which could be harmful to the patient.