Name the production code for 60 number in series
CREATE TABLE "table1_26702078_1" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "director" text,
  "writer_s" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_million" text
);
SELECT "production_code" FROM "table1_26702078_1" WHERE "no_in_series"=60;