Based on the input-output pairs, it seems that the function is linear with a slope of approximately -12.5 and an offset of around 193.3. Now, I will describe the function and provide its domain.

[DESCRIPTION]
The function appears to be a linear function with a negative slope of about -12.5 and a y-intercept of approximately 193.3.

[DOMAIN]
The domain of the function is the set of all real numbers. There doesn't seem to be any interval with unexpected behavior based on the tested input values.

[CODE]
```python
def approx_f(x):
    return -12.5 * x + 193.3
```
Please note that this code is an approximation based on the tested input-output pairs, and the actual function might differ slightly.