CREATE TABLE table_8559 ("Episode Number" FLOAT, "Air Date" CLOB, "Event 1" CLOB, "Event 2" CLOB, "Event 3" CLOB, "Event 4" CLOB)

What episode had sumo ball for event 3 and the wall for event 4?
SELECT AVG("Episode Number") FROM table_8559 WHERE "Event 4" = 'the wall' AND "Event 3" = 'sumo ball'
SELECT AVG("Episode Number") FROM "table_8559" WHERE "Event 3" = 'sumo ball' AND "Event 4" = 'the wall'