If you're talking about whole numbers, then it's 6,049 .
If you're talking about any number, including decimals and fractions, then there's no "greatest possible" one.
15,549 to the nearest hundred
The greatest whole number would be 499.
0
1200
10900
500
15,549 to the nearest hundred
To the nearest hundred, 100.
23,000 is already rounded to the nearest thousand, and is therefore the greatest possible value under the circumstances.
949.9999...
749 rounded to the nearest hundred is 700
Any from 450 to 549
6450 to 6549 to the nearest hundred
The greatest whole number would be 499.
It is 300 when rounded to the nearest hundred
916 rounded to the nearest hundred is 900
0