CREATE TABLE table_65883 ("Source" TEXT, "Chrome" TEXT, "Internet Explorer" TEXT, "Firefox" TEXT, "Safari" TEXT, "Opera" TEXT, "Other" TEXT)

What percentage of users were using Firefox according to the source that reported 21.70% used Internet Explorer?
SELECT "Firefox" FROM table_65883 WHERE "Internet Explorer" = '21.70%'
SELECT "Firefox" FROM "table_65883" WHERE "Internet Explorer" = '21.70%'