------
## 最终结论
```python
def median_numbers(a, b, c):
    sorted_numbers = sorted([a, b, c])
    return float(sorted_numbers[1])

# Test cases
assert median_numbers(25, 55, 65) == 55.0
assert median_numbers(20, 10, 30) == 20.0
assert median_numbers(15, 45, 75) == 45.0
```