CREATE TABLE table_2798 ("Club" TEXT, "Location" TEXT, "Manager" TEXT, "Stadium" TEXT, "Capacity" FLOAT, "Team captain" TEXT)

Who's captain of the team whose stadium has a capacity of 17800 people?
SELECT "Team captain" FROM table_2798 WHERE "Capacity" = '17800'
SELECT "Team captain" FROM "table_2798" WHERE "Capacity" = '17800'