Please help me solve this problem, I can't seem to get it...

Data:

file:///Users/kalis/Downloads/FinanceHWTemplate.pdf

Given the spreadsheet, , containing the realized return of the S&P 500 from 1926-2014. Starting in 1929, divide the next 80 years (1929-2008) of the sample into four periods of 20 years each. For each 20-year period, calculate the final amount an investor would have earned given a $3,000 initial investment. Also express your answer as an annualized return. If risk were eliminated by holding stocks for 20 years, what would you expect to find? What can you conclude about long-run diversification? The amount after the 1929-1948 period is $ and the return is %. (Round the amount to the nearest cent and the return to four decimal places.)