Question

The population of China is approximately 1.381 × 109, and the population of the United States is approximately 3.23 × 108.
About how many people live in both countries combined? Express your answer in scientific notation.
4.611 × 1017
1.704 × 109
4.46 × 108
1.849 × 101

Answer 1

To find the combined population of China and the United States, you can simply add the two populations together:

1. Population of China: \( 1.381 \times 10^9 \)
2. Population of the United States: \( 3.23 \times 10^8 \)

To add these numbers in scientific notation, it's helpful to convert them to the same exponent:

First, convert the population of the United States to match the exponent of the population of China:

\[
3.23 \times 10^8 = 0.323 \times 10^9
\]

Now, add the two populations together:

\[
1.381 \times 10^9 + 0.323 \times 10^9 = (1.381 + 0.323) \times 10^9 = 1.704 \times 10^9
\]

So, the combined population of China and the United States in scientific notation is:

\[
\boxed{1.704 \times 10^9}
\]