I cannot figure out the Indirect costs (2b.), the Fixed portion of sales representatives' compensation (3a.), or the total indirect selling expense (3b.) PLEASE HELP!

Kubin Company's relevant range of production is 17,000 to 26,500 units. When it produces and sells 21,750 units, its average costs per unit are as follows: Direct materials Direct labor Variable manufacturing overhead Fixed manufacturing overhead Fixed selling expense Fixed administrative expense Sales commissions Variable administrative expense Average Cost per Unit $ 7.80 $ 4.80 $ 2.30 $ 5.80 $ 4.30 $ 3.30 $1.80 $ 1.30 Required 1. Assume the cost object is units of production a. What is the total direct manufacturing cost incurred to make 21,750 units? b. What is the total indirect manufacturing cost incurred to make 21,750 units? 2. Assume the cost object is the Manufacturing Department and that its total output is 21,750 units a. How much total manufacturing cost is directly traceable to the Manufacturing Department? b. How much total manufacturing cost is an indirect cost that cannot be easily traced to the Manufacturing Department? 3. Assume the cost object is the company's various sales representatives. Furthermore, assume that the company spent $71,775 of its total fixed selling expense on advertising and the remainder of the total fixed selling expense comprised the fixed portion of the company's sales representatives' compensation a. When the company sells 21,750 units, what is the total direct selling expense that can be readily traced to individual sales representatives? b. When the company sells 21,750 units, what is the total indirect selling expense that cannot be readily traced to individual sales representatives