CREATE TABLE table_66237 ("State  ( class ) " TEXT, "Vacator" TEXT, "Reason for change" TEXT, "Successor" TEXT, "Date of successor's formal installation" TEXT)

When is it that successor's formal installation has a Vacator of ross bass (d)?
SELECT "Date of successor's formal installation" FROM table_66237 WHERE "Vacator" = 'ross bass (d)'
SELECT "Date of successor's formal installation" FROM "table_66237" WHERE "Vacator" = 'ross bass (d)'