CREATE TABLE table_50891 ("Institution" CLOB, "Location" CLOB, "Founded" FLOAT, "Affiliation" CLOB, "Enrollment" FLOAT, "Nickname" CLOB)

What is the average Founded, when Enrollment is 4,000?
SELECT AVG("Founded") FROM table_50891 WHERE "Enrollment" = '4,000'
SELECT AVG("Founded") FROM "table_50891" WHERE "Enrollment" = '4,000'