To order the numbers from greatest to least, we first convert them into a comparable format.
- -19 5/10 is equivalent to \(-19.5\).
- -21/18 can be converted to a decimal: \[ -\frac{21}{18} = -1.1667 \quad (\text{approx.}) \]
- 19.15 remains as is.
Now we have:
- \(-19.5\)
- \(-1.1667\)
- \(19.15\)
Now, let's arrange them from greatest to least:
- 19.15
- -1.1667
- -19.5
Thus, the ordered list from greatest to least is:
19.15, -1.1667, -19.5.