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

### Instruction:
For Stellenbosch, which has a population larger than 155,733, what is the average area?

### Inputs:
table_name: table, columns: ['Name', 'Seat', 'Population (2011)', 'Area (km 2 )', 'Density (inhabitants/km 2 )']

### Response:
SELECT AVG Area (km 2 ) FROM table WHERE Name = stellenbosch AND Population (2011) > 155,733