cross drugs currently fills mail orders from all over the u.s., and receipts come in to a head office in little rock, arkansas. the firm's average accounts receivable (a/r) is $2.5 million and is financed by a bank loan with 11 percent annual interest. cross is considering a regional lockbox system to speed up collections which it believes will reduce a/r by 20 percent. the annual cost of the system is $15,000. what is the estimated net annual savings to the firm from implementing the lockbox system?