CREATE TABLE table_62688 ("Seat" FLOAT, "Series 1" TEXT, "Series 2" TEXT, "Series 3" TEXT, "Series 4" TEXT)

What is the seat number when Series 3 shows Dana B rov ?
SELECT AVG("Seat") FROM table_62688 WHERE "Series 3" = 'dana bérová'
SELECT AVG("Seat") FROM "table_62688" WHERE "Series 3" = 'dana bérová'