Question: What is Melaine Walker's Rank?
SQL: SELECT SUM("Rank") FROM "2-18579281-4" WHERE "Name" = 'Melaine Walker';

Question: What is the Name of the Player with a Rank of 23 or less, Heat of 4 and Result of 55.91?
SQL: SELECT "Name" FROM "2-18579281-4" WHERE "Heat" = 4.0 AND "Rank" < 23.0 AND "Result" = '55.91';

Question: What is the Heat of the Player with a Rank of 18 or less and Result of 55.15?
SQL: SELECT "Heat" FROM "2-18579281-4" WHERE "Rank" < 18.0 AND "Result" = '55.15';