Derby Phones is considering the introduction of a new model of headphones with the following price and cost characteristics. Sales price Variable costs Fixed costs $ 21 per unit 6 per unit 20,000 per month. Assume that the projected number of units sold for the month is 6,000. Consider requirements (b), (c), and (d) independently of each other. Required A Required B Required C Required D What is the impact on operating profit if the sales price decreases by 10 percent? Increases by 20 percent? (Do not round intermediate calculations.) Sales price decreases by 10 percent: Operating profit ir by Sales price increases by 20 percent: Operating profit in by Required A Required B Required C Required D What is the impact on operating profit if variable costs per unit decrease by 10 percent? Increase by 20 percent? (Do not round intermediate calculations.) Variable costs per unit decrease by 10 percent: Variable costs per unit increase by 20 percent: by Operating profit Operating profit in by $