Selling, general, and administrative expenses were $57,000; net sales were $259,100; interest expense was $6,100; research and development expenses were $27,000; net cash provided by operating activities was $67,900; income tax expense was $6,500; cost of goods sold was $141,100. Required: a. Calculate operating income for the period. Operating expenses: b. Calculate net income for the period. Interest expense Income tax expense