12. At the beginning of 10 successive years, a premium of $120 is paid on a certain insurance policy. What is the worth of the sum of these payments at the end of the tenth year if computed at 4% compound interest? 13. What annual interest rate increases an investment of $1,400 to $2,000 in 9 years? 14. If the down payment on a piece of land is $7,000 and the annual payments for 8 years are $2,000 per year, what is the value of the land now if i = 5%