CREATE TABLE table_72412 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

How many incumbents had a district of Arkansas 3?
SELECT COUNT("Incumbent") FROM table_72412 WHERE "District" = 'Arkansas 3'
SELECT COUNT("Incumbent") FROM "table_72412" WHERE "District" = 'Arkansas 3'