need help with formula and excel spreadsheet

Use this handout as your coversheet after filling in the blanks with values you make-up and attaching whatever spreadsheets you generate when solving the problems below. 16. If you save $100 monthly and your bank promises %, how many months will it take to accumulate $25,000? 17. If you borrow $ and repay $800 monthly at a rate of 6%, how many months will it take to repay the loan? 18. If your mutual fund has produced annual returns of 10%, -5%, 20% and _%, what is your arithmetic average return? 19. What is the geometric average return of the returns in Problem #18. 20. What is the standard deviation of the returns in Problem #18