situation in which you would use marginal analysis, economics homework help

Describe a situation in which you would use marginal analysis to make a business decision. ( WALMART- Will be the Company)In creating your response, consider the following questions: What type of business decision would you make? How would you determine the marginal benefit and marginal cost of the decision? To what extent would you factor the opportunity cost of your decision? And what types of trade-offs would you likely face when you make your decision?