CREATE TABLE table_39145 ("FOURCC" TEXT, "DX 10 Name" TEXT, "Description" TEXT, "Alpha premultiplied?" TEXT, "Compression ratio" TEXT, "Texture Type" TEXT)

Which Alpha premultiplied has a 4:1 Compression ratio and a dxt3 FOURCC?
SELECT "Alpha premultiplied?" FROM table_39145 WHERE "Compression ratio" = '4:1' AND "FOURCC" = 'dxt3'
SELECT "Alpha premultiplied?" FROM "table_39145" WHERE "Compression ratio" = '4:1' AND "FOURCC" = 'dxt3'