This question is from the Data Analytics for Auditing Using ACL 4th Edition.

You decide you want to know the number of days that each transaction in the AR table has been outstanding as of 12/31/18, as well as the average number of days outstanding for items in the greater than 120 day category, Use the Age command but without the Statistic command. Age the AR table on the Invoice_Date with a cutoff date of 12/31/18, using ACL'sdefault aging categories. Carefully determine which field to accumulate to obtain the information required.

what is the average number of days outstanding for transactions in the greater than 120 day category?