Just looking for the Standard Deviation.

Assume these are the stock market and Treasury bill returns for a 5 -year period: Required: 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.) X Answer is complete but not entirely correct. Complete this question by entering your answers in the tabs below. What was the risk premium on common stock in each year? Note: Do not round intermediate calculations. Enter your answers as a percent rounded to 2 decimal places. Neg values should be entered with a negative sign. What was the average risk premium? Note: Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places. What was the standard deviation of the risk premium? (Ignore that the estimation is from a sample of data.) Note: Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places