need help with 5-4 1 and 2 plzz, thank you!!!

EXERCISE 5 -4 Computing and Using the CM Ratio [LO3] Last month when Harrison Creations, Inc, sold 40,000 units, total sales were $300,000, total variable expenses were $240,000, and fixed expenses were $45,000. Required: 1. What is the company's contribution margin (CM) ratio? 2. Estimate the change in the company's net operating income if it were to increase its total sales by $1,500