Write SQL query to solve given problem: State the publisher name for publisher ID 877? Calculate its average year to date sales.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.pub_name, AVG(T1.ytd_sales) FROM titles AS T1 INNER JOIN publishers AS T2 ON T1.pub_id = T2.pub_id WHERE T1.pub_id = '0877' GROUP BY T2.pub_name