TopBass Incorporated manufactures fishing equipment. During 2022 , total costs associated with manufacturing 16,000 fly-cast fishing rods (a new product introduced this year) were as follows: Required: a. Calculate the cost per fishing rod under both variable costing and absorption costing. b. If 350 of these fishing rods were in finished goods inventory at the end of 2022 , by how much and in what direction (higher or lower) would 2022 operating income be different under variable costing than under absorption costing? c. 1. Express the fishing rod cost in a cost formula. 2. What does this formula suggest the total cost of making an additional 275 fishing rods would be