CREATE TABLE table_38644 ("Week" FLOAT, "Date" CLOB, "Opponent" CLOB, "Result" CLOB, "Game site" CLOB, "Attendance" FLOAT)

Name the average week for result of l 28 17
SELECT AVG("Week") FROM table_38644 WHERE "Result" = 'l 28–17'
SELECT AVG("Week") FROM "table_38644" WHERE "Result" = 'l 28–17'