MyFurn is a producer of customized furniture on order. The company's sales and cost figures for the months Jan-Mar 2015 are as follows: JAN FEB MAR Number of units sold 250 400 300 Sales 6,250 10,000 7,500 Cost of Goods Sold 3,000 4,200 3,500 Gross Margin 3,250 5,800 4,000 Operating expenses 1,000 1,450 1,000 Net Income 2,250 4,350 3,000 a. Using regression analysis, calculate the fixed and variable cost elements for "COGS" and "operating expenses". (10 points) b. Calculate the contribution margin for the months JAN, FEB, and MAR. (5 points)