a. Here are the average rates of return for common stocks and Treasury billis for four different periods. What was the risk premium on stock for each of these periods?

1900-1924 1925-1949 1950-1974 1975-2010

Stocks 9.50% 10.20% 11.10% 13.70%

Treasury bills 5.10% 1.10% 3.50% 5.60%

b. What securities do the historical records show bond performances are typically against?