I am having a problem calculating b & C. Please help.

Here are stock market and Treasury bill percentage returns between 2006 and 2010:

Year	Stock Market Return	T-Bill Return
2006	16.57	5.60
2007	6.51	5.36
2008	38.03	1.90
2009	29.00	0.50
2010	18.26	0.72

a.	What was the risk premium on common stock in each year?(Negative values should be indicated by a minus sign. Round your answers to 2 decimalplaces.)

Year	Risk Premium
2006	10.97 %
2007	1.15 %
2008	-39.93 %
2009	28.50 %
2010	17.54 %

b.	What was theaveragerisk premium?(Do not roundintermediate calculations. Round youranswerto 2 decimal places.)

Average risk premium

%

c.	What was the standard deviation of the risk premium?(Do not round intermediate calculations. Round your answer to 2 decimal places.)

Standard deviation of the risk premium

%