Contribution margin ratio

a$.$ Coastal Company budgets sales of $$1,090,000,$ fixed costs of $$56,400,$ and variable costs of $$250,700.$ What is the contribution margin ratio for Coastal Company?

b$.$ If the contribution margin ratio for Bushner Company is $67\%,$ sales were $$557,000,$ and fixed costs were $$279,890,$ what was the operating income?