Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the average of the Series #s that were directed by Matthew Penn?

### Inputs:
table_name: table, columns: ['Series #', 'Season #', 'Title', 'Directed by', 'Original air date', 'Production code']

### Response:
SELECT AVG Series # FROM table WHERE Directed by = matthew penn