12. What is the break-even point? 13. What steps are required in constructing a break-even chart? 14. What is the difference between the contribution margin ratio and the margin of safety ratio? 15. What impact does income tax have on the break-even point? 16. Define differential analysis, differential revenue, differential cost, and differential income. 17. What is the importance of make-or-buy studies for a company? 18. What is an opportunity cost? Give an example. 19. What are distribution costs? 20. What is the purpose of the analysis of distribution costs? 21. In cost analysis, what determines which costs should be included in a study