4. You are considering a lockbox system that will decrease your collection time by two days. Your average cheek size is S1 19 and you receive 5.650 checks per day. If the daily interest rate is .015 percent and the lockbox service charges a fee of $160 per day, should the lockbox project be accepted? 0. Each year you sell 950 units of a product at a price of $899 each. The variable cost per unit is $575 and the carrying cost per unit is $16.90. You have been buying 100 units at a time. Your fixed cost of ordering is $60. What is the economic order quantity