CREATE TABLE table_2214 ("Poll source" TEXT, "Dates administered" TEXT, "Tom Emmer  ( R ) " TEXT, "Matt Entenza  ( DFL ) " TEXT, "Tom Horner  ( I ) " TEXT, "Undecided" TEXT, "Sampling error" TEXT)

What's the percentage of undecided according to the poll source with sampling error of 2.7%?
SELECT "Undecided" FROM table_2214 WHERE "Sampling error" = '2.7%'
SELECT "Undecided" FROM "table_2214" WHERE "Sampling error" = '2.7%'