CREATE TABLE table_20753 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Ground" TEXT, "Date" TEXT, "Crowd" FLOAT)

When the crowd was 8642 what was the away team's score?
SELECT "Away team score" FROM table_20753 WHERE "Crowd" = '8642'
SELECT "Away team score" FROM "table_20753" WHERE "Crowd" = '8642'