The following spreadsheet contains monthly returns for Cola Co. and Gas Co. for 2013. Using these data, estimate the average monthly return and the volatility for each stock. (Click on the following icon in order to copy its contents into a January February spreadsheet.) The average monthly return for Cola Co. is %. (Round to two decimal places.) Month Cola Co. -6.80% 7.40% -2.10% March April 4.30% May 11.30% June 1.40% July 4.10% August -0.60% September 0.80% October 1.90% November 0.70%