4. Vinci Co. manufacturers and sells a single product. Price and cost data regarding this product are as follows: Selling price Variable manufacturing costs... Variable selling and administrative expenses.......... Fixed manufacturing overhead. Fixed selling and administrative expenses. $40 per unit $20 per unit $6 per unit $208,000 per year $324,000 per year 4.a. Calculate the break-even point in units. 4.b. How many units need to be sold to earn an annual net operating income equal to 10% of sales? 4.c. In the current year, the company sold 43,000 units. Due to competition, management will be forced to lower the selling price by 10% next year. How many units must be sold next year to earn the same income as was earned in the current year