CREATE TABLE table_66377 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" FLOAT)

What is the attendance in a week earlier than 4, and result is w 31-20?
SELECT AVG("Attendance") FROM table_66377 WHERE "Week" < '4' AND "Result" = 'w 31-20'
SELECT AVG("Attendance") FROM "table_66377" WHERE "Result" = 'w 31-20' AND "Week" < '4'