help with 8a please

8. Standard deviation of returns The following table shows the nominal returns on Brazilian stocks and the rate of inflation. a. What was the standard deviation of the market returns? (Do not make the adjustment for degrees of freedom described in footnote 15.) b. Calculate the average real return. Year Nominal Return (%) Inflation (%) 2012 0.1 5.8 2013 -16.0 5.9 2014 -14.0 6.4 2015 41.4 10.7 2016 66.2 6.3 2017 26.9 2.9