Graph an inequality on a number line: 15>m

When the sign is ≤ or ≥ ("less/greater than or equal to"), the dot if filled in.

When the sign is, the dot is not filled in/open circle.

15 > m

[15 is greater than m, or m is less than 15]

Since m is less than 15, the arrow is going to the left (the numbers to the left are less than 15)