CREATE TABLE "table1_19229713_4" (
  "no" real,
  "num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_million" text
);

Question: Name the number for viewers being 1.87
SQL: SELECT MAX("num") FROM "table1_19229713_4" WHERE "u_s_viewers_million"='1.87';

Question: Name the production code for viewers for 1.69
SQL: SELECT "production_code" FROM "table1_19229713_4" WHERE "u_s_viewers_million"='1.69';