CREATE TABLE table_72226 ("Member" TEXT, "Week Arrived On Main Island" TEXT, "Week Sent To Third Island" TEXT, "Original Tribe" TEXT, "Tribe They Chose To Win" TEXT)

How many members arrived on the main island in week 4?
SELECT COUNT("Member") FROM table_72226 WHERE "Week Arrived On Main Island" = '4'
SELECT COUNT("Member") FROM "table_72226" WHERE "Week Arrived On Main Island" = '4'