I did it in a lab exercise and I think we were 20% off with the proper result somewhere close to the end of the error bar (inside or outside I don't remember).

I did it in a lab exercise and I think we were 20% off with the proper result somewhere close to the end of the error bar (inside or outside I don't remember). It felt disappointing at the time, like all early lab exercises. Some later ones were much closer to the state of the art.