CREATE TABLE table_15612 ("Location" TEXT, "Nickname" TEXT, "Founded" FLOAT, "Type" TEXT, "Enrollment" FLOAT, "Joined" FLOAT, "Left" FLOAT, "Current Conference" TEXT)

What is the average Joined with a Nickname of wildcats in longmeadow, massachusetts?
SELECT AVG("Joined") FROM table_15612 WHERE "Nickname" = 'wildcats' AND "Location" = 'longmeadow, massachusetts'
SELECT AVG("Joined") FROM "table_15612" WHERE "Location" = 'longmeadow, massachusetts' AND "Nickname" = 'wildcats'