assume these are the stock market snd Treasury bill returns for a 5-year period:

year 2013 with Stock Market Return of 32.80% and T-Bill Return of 0.09%

year 2014 with Stock Market Return of 12.20% and T-Bill Return of 0.09%

year 2015 with Stock Market Return of -2.90% and T-Bill Return of 0.09%

year 2016 with Stock Market Return of 14.00% and T-Bill Return of 0.04%

year 2017 with Stock Market Return of 23.00% and T-Bill Return of 0.06%

a) What was the risk premium on common stock in each year?

b) What was the average risk premium?

c) What was the standard deviation of the risk premium?( Ignore that the estimation is from a sample of data)