Calculate the standard deviation of a stock's return for the years 1926 to 1930. Round to the nearest hundredth. Answer in percent. Year 1926 1927 1928 1929 1930 Return 12.55% 32.93% 43.67% 7.02% 29.03% Over each decade since the 1930s, the class of investment that consistently yielded positive real returns are Equities O Bonds O Cash (Treasury Bonds)