Question

The average newborn weighs 7.5 pounds about 4.1×10 to the sixth power babies are born in the United States every year. What is the approximate total weight in pounds of all the babies born in the US in a year? Write the answer in scientific notation

Answer 1

To find the total weight of all the babies born in the US in a year, we'll multiply the average weight of a newborn by the number of babies born.

1. The average weight of a newborn is \( 7.5 \) pounds.
2. The number of babies born each year is \( 4.1 \times 10^6 \).

Now we calculate the total weight:

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

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

To multiply these numbers, we can first multiply the coefficients:

\[
7.5 \times 4.1 = 30.75
\]

Now, we include the power of ten:

\[
\text{Total weight} = 30.75 \times 10^6
\]

Next, we convert \( 30.75 \) into scientific notation:

\[
30.75 = 3.075 \times 10^1
\]

Thus:

\[
30.75 \times 10^6 = 3.075 \times 10^1 \times 10^6 = 3.075 \times 10^{7}
\]

So the approximate total weight in pounds of all the babies born in the US in a year is:

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