“Our master bath has a shower, sink, and toilet, but no tub. Is that called a 3/4 bath?”
Way back in 1984 when I got into real estate, we did call that a 3/4 bath.
However about 20 years ago it became commonplace to just round it up and call it a full bath.
Half baths are still called half baths, though the San Diego Multiple Listing Service counts them as full baths when giving a bathroom count.