If $100 is invested at a rate of 5% compounded continuously, the amount in the account is
given by: S=100e0.05t. If the same principal is invested at an account earning 5%
compounded semiannually, the amount is given by: S= 100 ·1.0252x. Consider the
difference in these two investments by graphing both functions on your graphing
calculator and looking at the years 5 through 7. (Use the window
5, 7 ×128,142 .) What do you notice about the two graphs?
If $25,000 is used to purchase an annuity consisting of equal payments at the end of each
year for the next 8 years and the interest rate is 5% compounded annually, find the amount
of each payment.
Suppose that you can invest $11,000 in a business that guarantees you the following cash
flows: $5500 at the end of 2 years, $4500 at the end of 4 years, and $4000 at the end of 5
years. Assuming an interest rate of 6.25% compounded annually, find the net present value
of the cash flows. Is the investment profitable?
A trust fund for a 12–year–old child is being set up by a single payment so that when the
child is 21 there will be $24,000. If the fund earns interest at the rate of 7.25% compounded
quarterly, how much money should be paid into the fund initially?
The premiums on an insurance policy are $20 a month, payable at the beginning of each
month. If the policy holder wishes to pay 1 year’s premiums in advance, how much should
be paid provided that the interest rate is 5.1% compounded monthly?
Suppose an initial investment grows from $330 to $600 over five years. First find the
nominal rate compounded monthly and then find the equivalent effective rate.
Suppose an annuity due consists of 6 yearly payments of $200 and the interest rate is 5%
compounded annually. Determine (a) the present value and (b) the future value at the end
of 6 years.