Over the past four years, the annual percentage returns on large-company stocks were 15, 7, 4, and 18 percent. for the same time period, u. s. treasury bills produced the returns of 6, 3, 2, and 4 percent. inflation averaged 2.8 percent over the four-year period. the average real rate of return on large-company stocks was percent as compared to percent for treasury bills. a. 6.47; .92b. 6.47; 1.08c. 7.98; .92d. 7.98; 1.08e. 7.98; 1.22a stock produced returns of 14 percent, 17percent, and -1 percent over three of the past four years, respectively. the arithmetic average for the past four years is 6 percent. what is the standard deviation of the stock's returns for the four-year period? a. 11.63 percentb. 15.94 percentc. 9.70 percentd. 6.25 percente. 11.23 percentover the last four years, the common stock of plymouth shippers has had an arithmetic average return of 10.4 percent. three of those four years produced returns of 16.1 percent, 15.6 percent, and 9.4 percent, respectively. what is the geometric average return for this four-year period? a. 9.72 percentb. 10.41 percentc. 8.93 percentd. 10.22 percente. 9.38 percent