Report the average and standard deviation of monthly return for your corporation and the S&P 500 on the spreadsheet.  Use the spreadsheet functions to calculate these: =AVERAGE(data range), =STDEV(data range).A good idea to check that you are doing everything correctly is to see that you got the same values as another group for the S&P 500 Index because thesedata will be the same for everyone.  You should get the same answers except for perhaps a minor rounding difference depending on the number of decimal places the cells are using.