Milden Company has an exclusive franchise to purchase a product from the manufacturer and distribute it on the retail level. As an aid in planning, the company has decided to start using a contribution format income statement. To have data to prepare such a statement, the company has analyzed its expenses and has developed the following cost formulas Cost Formula Cost Cost of good sold Advertising expense Sales commissions Shipping expense Administrative salaries 35 per unit sold $210,000 per quarter 6% of sales surance expense Depreciation expense $145,000 per quarter $9,000 per quarter $76,000 r quarter Management has concluded that shipping expense is a mixed cost, containing both variable and fixed cost elements. Units sold and the related shipping expense over the last eight quarters follow Shipping Units Sold Expense Quarter Year 1: First Second Third Fourth 10,000 $119,000 16,000 $175,000 18,000 $190,000 15,000 $164,000 Year 2: First Second Third Fourth 11,000 $130,000 17,000 $185,000 20,000 $210,000 13,000 $147,000 Milden Company's president would like a cost formula derived for shipping expense so that a budgeted contribution format income statement can be prepa red for the next quarter