A firms balance sheets for year-end 2011 and 2012 contain the following data. All items are in millions of dollars. Dec. 31, 2011 Dec. 31, 2012 Accounts receivable 33.4 36.7 Inventories 26.4 30.7 Accounts payable 13.4 26.7 a. Calculate the net working capital in 2011. (Enter your answer in millions rounded to 1 decimal place.) Net working capital $ million b. Calculate the net working capital in 2012. (Enter your answer in millions rounded to 1 decimal place.) Net working capital $ million c. What happened to investment in net working capital during 2012? (Input the amount as a positive value. Enter your answer in millions rounded to 1 decimal place.) Net working capital has by $ million.