Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_3 (fixtures INTEGER, clubs_involved VARCHAR)
### Question:
When 4 clubs are involved, what is the average number of fixtures?
### Answer:
SELECT AVG(fixtures) FROM table_name_3 WHERE clubs_involved = 4