cash received from customers includes all $139,000 of the accounts receivable that were outstanding at november 30, 20x1. accounts receivable at december 31, 20x1, totaled $141,000. accounts payable (to suppliers of inventory) decreased by $19,000 from november 30, 20x1, to december 31, 20x1. the balance in the inventory account decreased by $39,000 over the same period. required: what is gross profit for the month of december under accrual accounting?