Name the karen when nicky is 2.5
CREATE TABLE "table1_19744915_4" (
  "order" real,
  "couple" text,
  "karen" text,
  "nicky" text,
  "jason" text,
  "ruthie" text,
  "robin" text,
  "total" text,
  "skating_song" text,
  "scoreboard" text,
  "public_vote" text
);
SELECT "karen" FROM "table1_19744915_4" WHERE "nicky"='2.5';