P8-9 (similar to) Question Help Historical returns. Calculate the arithmetic average return of U.S. Treasury bills, long-term government bonds, and large company stocks for 1989 to 1998. Which had the highest retum? Which had the lowest return? On the left side, click on the spreadsheet Learning Aid to see Table 8.1 Year by Year Returns, 1950-1999 What is the average return of U.S. Treasury bills for 1900 to 1990? (Round to two decimal places) P8-9 (similar to) Question Help Historical returns. Calculate the arithmetic average return of U.S. Treasury bills, long-term government bonds, and large company stocks for 1989 to 1998. Which had the highest retum? Which had the lowest return? On the left side, click on the spreadsheet Learning Aid to see Table 8.1 Year by Year Returns, 1950-1999 What is the average return of U.S. Treasury bills for 1900 to 1990? (Round to two decimal places)