How much money should be deposited now to pay for these machines, if the interest rate is 8% compounded semiannually? How much money should they deposit in an account paying 10.2% so they will have $1...How much money should be deposited now to pay for these machines, if the interest rate is 8% compounded semiannually? How much money should they deposit in an account paying 10.2% so they will have $100,000 in 18 years to pay for their daughter's educational expenses? 15) The population of the African nation of Cameroon was 12 million people in the year 2015; it has been growing at the rate of 2.5% per year.