please answer part C, showing what to fill the boxes with and how to get answers (formulas or show math)

Total 15.000 15,000 Hamilton Stage Supplies is a manufacturer of a specialized type of light used in theaters three years of business is as follows: 2020 2021 Units sold 5,000 5,000 Units produced 5,000 6,000 Fixed production costs $50,000 $50,000 Variable production costs per unit 75 75 Selling price per unit 225 225 Fixed selling and administrative expense 5,000 5,000 Required a. Calculate profit and the value of ending inventory for each year using full costing. 2022 5,000 4,000 $50,000 75 225 5,000 2020 2021 2022 Fixed production overhead units produced fixed production overhead per unit variable production costs per unit Full cost per unit sales less: cost of goods sold gross margin less: selling and administrative expense Net income Units Sold Units Produced Value of ending inventory cost structure remain constant. b. Explain why profit fluctuates from year to year even though the number of units sold, the selling price, and the Net income will continue to fluctuate from year to year even with the number of units sold, the selling price and the cost of structure remaining constant. This is due to full cost per unit fluctuating. Full cost can chage based on if production increases or decreases c. Calculate profit and the value of ending inventory for each year using variable costing. Net income Value of ending inventory