(Appendix) Comparison of Full-Absorption and Variable Costing, Using the Algebraic Method—Part III: Refer to the information given in exercise 9-17. Assume it is now the third quarter of the same year, and the volumes in the third quarter are as follows:

Variable costs and selling price per unit remain the same in the third quarter as in the first quarter, as do quarterly fixed costs.

Required: Using the algebraic method, show the difference in operating profits between vari- able costing and full-absorption costing. (You may assume either a FIFO or LIFO inventory flow.)

Sales volume Production volume 100,000 units 80,000 units