CREATE TABLE table_17392 ("No. in series" TEXT, "No. in season" TEXT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT)

What's the season number of the episode titled 'Grad school'?
SELECT "No. in season" FROM table_17392 WHERE "Title" = 'Grad School'
SELECT "No. in season" FROM "table_17392" WHERE "Title" = 'Grad School'