13. The Cool School Logo Products Company needs to predict the labor cost in producing specialty coffee mugs. The following production information is available: Year Production Volume Labor Hours Labor Dollars 2008 2,500 1,700 $8,500 2009 3,400 1,950 11,700 2010 2,400 1,500 12,000 2011 4,400 2,500 22,500 2012 3,200 1,900 17,100 2013 2,800 1,750 17,500 Wage rates have steadily increased since 2008; however, management expects no further increases in 2014. a. Select the appropriate independent variable for estimating labor cost. Explain the reason for your selection. b. Develop an equation to predict for 2014 the labor cost of producing specialty mugs. Use the high- low method