138)Stuart Manufacturing produces metal picture frames. The company's income statements for the lasttwo years are given below:Last yearThis yearUnits sold50,00070,000Sales$800,000$1,120,000Less cost of goods sold550,000710,000Gross margin250,000410,000Less operating expenses150,000190,000Net income$100,000$ 220,000The company has no beginning or ending inventories.Required:a. Estimate the company's total variable cost per unit, and its total fixed costs per year. (Remember ththis is a manufacturing firm.)b. Compute the company's contribution margin for this year