Questions: A nurse is converting an infant's weight in lb and oz to kg. The infant weighs 9 lb 4 oz. What is the infant's weight in kg? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Solution Steps

To convert the infant's weight from pounds and ounces to kilograms, we need to follow these steps:

1. Convert the weight in pounds and ounces to total ounces.
2. Convert the total ounces to kilograms using the conversion factor (1 ounce = 0.0283495 kilograms).
3. Round the result to the nearest tenth.

First, we convert the weight from pounds to ounces. Given that 1 pound is equal to 16 ounces, we have: $$9 \, \text{lb} \times 16 \, \frac{\text{oz}}{\text{lb}} = 144 \, \text{oz}$$

Next, we add the additional 4 ounces to the total ounces: $$144 \, \text{oz} + 4 \, \text{oz} = 148 \, \text{oz}$$

We then convert the total ounces to kilograms using the conversion factor $1 \, \text{oz} = 0.02835 \, \text{kg}$: $$148 \, \text{oz} \times 0.02835 \, \frac{\text{kg}}{\text{oz}} = 4.1957 \, \text{kg}$$

Finally, we round the result to the nearest tenth: $$4.1957 \approx 4.2$$

Final Answer