It seems so:

```
In [1]: (18 + 17. / 60 + 43.08 / 3600.) * 15.
Out[1]: 274.4295
```

the precision is consistent with the truncation of the string at 2 decimal places, I can recover the right value with:

```
In [6]: (18 + 17. / 60 + 43.0824 / 3600.) * 15.
Out[6]: 274.42951000000005
```