To express the numbers in scientific notation, we rewrite each number by moving the decimal point to the left until we have a number between 1 and 10, and then we multiply by the appropriate power of 10.
-
98,789,000:
- Move the decimal 7 places to the left: \( 9.8789 \times 10^7 \)
-
987,890,000:
- Move the decimal 8 places to the left: \( 9.8789 \times 10^8 \)
-
89,987,000:
- Move the decimal 7 places to the left: \( 8.9987 \times 10^7 \)
Now we compare the scientific notations:
- \( 9.8789 \times 10^7 \)
- \( 9.8789 \times 10^8 \)
- \( 8.9987 \times 10^7 \)
Since \( 10^8 \) is greater than \( 10^7 \), we can eliminate \( 987,890,000 \) from having the least value.
Now we compare \( 9.8789 \times 10^7 \) and \( 8.9987 \times 10^7 \). The coefficients are:
- \( 9.8789 \)
- \( 8.9987 \)
Since \( 8.9987 < 9.8789 \), the number \( 89,987,000 \) has the least value.
Therefore, the answer in scientific notation, expressed to the exact decimal place, is:
\( 8.9987 \times 10^7 \).