XYZ Ltd. operates in the retail sector and had the following information regarding its sales and expenses for the year ended December 31, 2022:

Sales revenue: $1,000,000
Cost of goods sold: $600,000
Operating expenses: $200,000
Depreciation expense: $50,000
Interest expense: $20,000

The company's income tax rate is 30%.

a) Calculate the company's gross profit, operating income, and net income for the year ended December 31, 2022.

b) Calculate the company's gross profit margin, operating income margin, and net income margin for the year ended December 31, 2022.