Fill in the blanks for each of the following independent cases. (Click the icon to view the cases.) (For entries with a $0 balance, make sure to enter "O" in the appropriate cell. Round the contribution margin percentage to the nearest whole percent.) Variable Fixed Total Operating Contribution Case Revenues Costs Costs Costs Income Margin Percentage i Data Table a. $ 500 $ 900 $ 1,300 % Variable Costs Fi Costs Total Costs Operating Income Contribution Margin Percentage Case Revenues Case a. $ 500 900 $ 1,300 Case b. $ 2,900 $ 400 $ 1,200 Case c. $ 1,100 $ 700 1,100 Case d. $ 1,600 400 75% Print Done