Navigation Question - Ex-Meridians

Thanks for the guidance. I’ve been doing a bunch of the CG questions, but none of them seem to be working out. I’m using the right tables (in the new version of Bowditch), right almanac, etc. Yet I can’t get any closer than 10’ in my calculations (it’s not my math). Any other advice? I would think that their questions would work out if not exact, pretty close.