Automatic changing of status from 'solution Provided' to 'Closed' in Given time

Hello ,

How to close the Incident automatically after any particular status in a limited time duration.

For Ex.

If a status of the incident is 'solution Provided' and Customer is not closing the Incident then how the incident will get closed automatically after 7 day of status 'Solution Provided'.

Is there any report which can help me close the incident after 7 days.

Thanks in advance for your Help