Auto Parts Inc. began the current month with inventory costing $40,000, then purchased inventory at a cost of $175,000. The perpetual inventory system indicates that inventory costing $120,000 was sold during the month for $160,000. If an inventory count shows that inventory costing $92,000 is actually on hand at month-end, what amount of shrinkage occurred during the month? The answer is $ 3000 but could you please give the detailed solution of how to calculate the required result?