Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:

Convert text to sql: What is the average age for all people in the table? | person : name , age , city , gender , job | personfriend : name , friend , year | personfriend.friend = person.name | personfriend.name = person.name | 

### Response:

select avg ( _ ) from _ | select avg ( age ) from person