Question: What was the state (class) where the new successor was formally installed on May 11, 1966?
Schema: create table table_1847180_3 (state__class_ varchar, date_of_successors_formal_installation varchar, PRIMARY KEY (state__class_))
SQL: select state__class_ from table_1847180_3 where date_of_successors_formal_installation = "may 11, 1966"