What is the average against of Murrayfield, Edinburgh?
CREATE TABLE table_name_13 (against INTEGER, venue VARCHAR)
SELECT AVG(against) FROM table_name_13 WHERE venue = "murrayfield, edinburgh"
### Context: CREATE TABLE table_name_13 (against INTEGER, venue VARCHAR) ### Question: What is the average against of Murrayfield, Edinburgh? ### Answer: SELECT AVG(against) FROM table_name_13 WHERE venue = "murrayfield, edinburgh"