I am stuck... Has to do with journal entries

WWC decides to use the aging method to estimate uncollectible accounts. WWC determines 8% of the ending balance is the appropriate end of February estimate of uncollectible accounts on Feb29th.

What do i use to get this amount?? is it just accounts receivable? And is just for accounts receivable acquired in the month of feb our is it also include the beggining balance that is carried over from january???