4. assume the company wants to adapt the information in the "cost summary" tab to prepare a contribution format income statement. within the "income statements" tab of your template, and using the sum ifs function to quantify all variable and fixed expenses: a. prepare a contribution format income statement. (hint: the cost of goods sold should include all direct materials, direct labor, and variable manufacturing overhead. the fixed manufacturing overhead costs should be included within the "fixed expenses" portion of the income statement.) b. based on the contribution format income statement, what is the contribution margin? c. based on the contribution format income statement, what is the net operating income?