For the 1998 movie which got the highest popularity, how many "4" rating did the movie get?
1998 movie refers to movie_release_year = '1998'; the highest popularity refers to MAX(movie_popularity) ; "4" rating refers to rating_score = 4
SELECT COUNT(T2.movie_title) FROM ratings AS T1 INNER JOIN movies AS T2 ON T1.movie_id = T2.movie_id WHERE T1.rating_score = 4 AND T2.movie_release_year = 1998 ORDER BY T2.movie_popularity DESC LIMIT 1