CREATE TABLE "table1_225099_3" (
  "state_class" text,
  "vacator" text,
  "reason_for_change" text,
  "successor" text,
  "date_of_successors_formal_installation" text
);

Question: Who was the successor for the state of Maine (2) ?
SQL: SELECT "successor" FROM "table1_225099_3" WHERE "state_class"='Maine (2)';

Question: What is the date of successors formal installation when the reason for change is resigned december 4, 1819?
SQL: SELECT "date_of_successors_formal_installation" FROM "table1_225099_3" WHERE "reason_for_change"='Resigned December 4, 1819';

Question: How many entries are shown for date of successors formal installation where successor is john w. walker (dr)?
SQL: SELECT COUNT("date_of_successors_formal_installation") FROM "table1_225099_3" WHERE "successor"='John W. Walker (DR)';

Question: Who was the successor for the state (class) of maine (2)?
SQL: SELECT "successor" FROM "table1_225099_3" WHERE "state_class"='Maine (2)';

Question: what is the state for reason for change is resigned may 15, 1820?
SQL: SELECT "state_class" FROM "table1_225099_3" WHERE "reason_for_change"='Resigned May 15, 1820';