Problem 4: Our company manufactures products A and B and start with zero beginning inventory. In 2019, we produced 1000 units of A and 2000 units of B. We sold 1000 units of A and 1500 units of B. The per-unit manufacturing cost of B is $60 under our existing cost system and this unit cost will be $50 if we change our cost system to ABC. How much will the firm's 2019 gross margin change (increase or decrease) if we adopt ABC