Mac: ~/Library/Application Support/MobileSync/Backup/

I prepared to update my IPad to ISO 5.1, but I must back up my music, apps, etc. I way informed that the back date would be located on my Mac is as follows: Mac: /Library/Application Support/MobileSync/Backup. Can anyone tell exactly how I can locate that info on my Mac to confirm the the back date is there. Please help. Thanks