Need help with b1 and b2 please explain with details.Thx

Consider the following table for a period of six years: Returns Large- Company Stocks U.S Treasury Bills Year 1 -15.29% 7.41% 2 -26.65 8.05 3 37.35 24.05 5.99 4 5.67 5 7.40 5.51 6 6.69 7.82 a-1. Calculate the arithmetic average returns for large-company stocks and T-bills over this time period. (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) a-2. Calculate the standard deviation of the returns for large-company stocks and T-bills over this time period. (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) Large T-bills company stocks Arithmetic average return - 6.74 3.13 1 - Standard deviation 24.32 1.14 2. Calculate the observed risk premium in each year for the large-company stocks versus the T-bills. b-1. What was the arithmetic average risk premium over this period? (A negative answer should be indicated by a minus sign. Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) b-2. What was the standard deviation of the risk premium over this period? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)