4. For each of the six independent situations below, compute the missing amounts. a. Using contribution margin per unit: Sales Variable Costs Contribution Margin per Unit Fixed Costs Operating Income Units Sold $120,000 $20 1. 2. 3. $4,000 $5,000 $180,000 $600,000 $25,000 $30,000 $90,000 $45,000 $150,000 $30 b. Using the contribution margin ratio: Sales Variable Costs Contribution Margin per Unit Fixed Costs Operating Income $720,000 1. 2. $900,000 $600,000 40% 30% $95,000 $75,000 $60,000 3. $90,000 5. Arrow Products typically earns a contribution margin ratio of 25% and has current fixed costs of $80,000. Arrow's general manager is considering spending an additional $20,000 to do one of the following: 1. Start a new ad campaign that is expected to increase sales revenue by 5%. 2. License a new computerized ordering system that is expected to increase Arrow's contribution margin ratio to 30%. Sales revenue for the coming year was initially forecast to equal $1,200,000 (that is, without implementing either of the above options). a. For each option, how much will projected operating income increase or decrease relative to initial predictions? b. By what percentage would sales revenue need to increase to make the ad campaign as attractive as the ordering system