manufacturer has supplied the following data A cement Tons of cement produced and sold Sales revenue Variable manufacturing expense $429.000 Fixed manufacturing expense Variable selling and administrative expense Fised selling and administrative expense...S228. Net operating income 260,900 S1,118,000 $91,900 $82,000 Required a. What is the company's unit contribution margin? b. What is the company's contribution margin ratio? c. If the company increases its unit sales volume bye%without increasin what will total net operating income be? its fixed expenses