CREATE TABLE table_6143 ("Call sign" CLOB, "Frequency" CLOB, "City of license" CLOB, "Watts" FLOAT, "Class" CLOB)

How many Watts has a Class of a, and a Frequency of 91.5 fm, and a City of license of elkhart, kansas?
SELECT MIN("Watts") FROM table_6143 WHERE "Class" = 'a' AND "Frequency" = '91.5 fm' AND "City of license" = 'elkhart, kansas'
SELECT MIN("Watts") FROM "table_6143" WHERE "City of license" = 'elkhart, kansas' AND "Class" = 'a' AND "Frequency" = '91.5 fm'