I took the index on the words, converted the range to binary, added 3 zeros, calculated the sha256 digest, took the first Component of the hexadecimal to transform it to binary, extra 3 zeros to the 8 digits on the binary and received 00000010011 which interprets to 19 in decimal. https://canvas.instructure.com/eportfolios/3396498/ricardooxtv236/opening-the-world-of-bip39-a-comprehensive-overview-to-mnemonic-expressions-and-word-checklists