CREATE TABLE table_45472 ("City proper" TEXT, "Population City limits in millions" FLOAT, "Density per km\\u00b2" FLOAT, "Urban area" TEXT, "Population Urban area in millions" FLOAT, "Metro area" TEXT, "Population Metro area in millions" TEXT)

Which urban area has a population of 5.3 million?
SELECT "Urban area" FROM table_45472 WHERE "Population Urban area in millions" = '5.3'
SELECT "Urban area" FROM "table_45472" WHERE "Population Urban area in millions" = '5.3'