We are said to find the missing data. Please help with a step-by- step explanation as I am confused on where to even start.

Cost-Volume-Profit Relations: Missing Data Following are data from 4 separate companies. Supply the missing data Case 1 Case 2 Case 3 Case 4 Sales revenue $100,000 $70,000 5 O Contribution margin $40,000 $ O $30,000 S O Fixed Costs $23,000 5 U Net income 57,000 56,000 5 Variable cost ratio O 0.50 0 0.20 Contribution margin ratio 0 0.40 Break-even point (dollars) $ O $20,000 Margin of safety (dollars) 5 $20,000