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

### Instruction:
how many millions of north american viewers had the episode whose director was Michael Lembeck?

### Inputs:
table_name: table, columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code(s)', 'U.S. viewers (millions)']

### Response:
SELECT U.S. viewers (millions) FROM table WHERE Directed by = Michael Lembeck