What are the profits (in billions) of the company with a market value of 172.9 billion?
CREATE TABLE "2011_list" (
  "rank" real,
  "company" text,
  "headquarters" text,
  "industry" text,
  "sales_billion" text,
  "profits_billion" text,
  "assets_billion" text,
  "market_value_billion" text
);
SELECT "profits_billion" FROM "2011_list" WHERE "market_value_billion"='172.9';