CREATE TABLE table_34515 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Record" TEXT, "Game Site" TEXT, "Attendance" TEXT)

Game Site of hoosier dome, and a Result of l 7 31 involved what attendance?
SELECT "Attendance" FROM table_34515 WHERE "Game Site" = 'hoosier dome' AND "Result" = 'l 7–31'
SELECT "Attendance" FROM "table_34515" WHERE "Game Site" = 'hoosier dome' AND "Result" = 'l 7–31'