CREATE TABLE table_name_5 (sales__billion_ NUMBER, company VARCHAR2, profits__billion_$_ VARCHAR2)

What is the average sales in billions of walmart, which has more than 15.7 billion in profits?
SELECT AVG(sales__billion_) AS $_ FROM table_name_5 WHERE company = "walmart" AND profits__billion_$_ > 15.7
SELECT AVG("sales__billion_") AS "$_" FROM "table_name_5" WHERE "company" = "walmart" AND "profits__billion_$_" > 15.7