The average newborn weighs 7.5 pounds. About 4.1×10^6 babies are born in the United States every year. What is the approximate total weight in pounds of all the babies born in the U.S. in a year? Write the answer in scientific notation, expressed to the exact decimal place.(1 point)

Question

×10
pounds

Answer 1

To find the total weight of all the babies born in the U.S. in a year, we can multiply the average weight of a newborn by the number of babies born.

1. Average weight of newborn: 7.5 pounds
2. Number of babies born: 4.1 × 10^6

Now, we can calculate the total weight:

\[ \text{Total weight} = \text{Average weight} \times \text{Number of babies} \]

\[ \text{Total weight} = 7.5 \text{ pounds} \times 4.1 \times 10^6 \]

Calculating this step by step:

1. Calculate \( 7.5 \times 4.1 \): \[ 7.5 \times 4.1 = 30.75 \]

2. Now, we include the scientific notation: \[ \text{Total weight} = 30.75 \times 10^6 \]

3. To express \( 30.75 \) in scientific notation: \[ 30.75 = 3.075 \times 10^1 \]

4. Now, substitute back into the equation: \[ \text{Total weight} = 3.075 \times 10^1 \times 10^6 = 3.075 \times 10^{1+6} = 3.075 \times 10^7 \]

Thus, the approximate total weight of all the babies born in the U.S. in a year, expressed in scientific notation, is:

\[ \boxed{3.075 \times 10^7} \text{ pounds} \]