The last few exercises I've been doing are giving me an error margin of between 0.5 and 0.8, and I'm not sure if that's normal since I can't compare with other users. In this particular exercise the error margin is higher than 0.8, and after checking the sketch/croquis I don't see any difference, so I'm not sure if there's some kind of mistake/failure in the system. Does anyone have the same result as me?