Texas Instruments TI-89 Titanium User Manual page 752

Finding the Interest Rate of an Annuity
Perform the following steps to find the interest rate (
principal ( ) is 1,000, number of compounding periods (
p
2,000.
1. On the Home screen, enter the equation
to solve for .
p
2. Enter the equation to solve for
3. Enter the equation to solve for i using the
with operator.
solve(s=p (1+i)^n,i) | s=2000
†
and
n=6
Result: The interest rate is 12.246%.
Note:
• To enter the "with" ( | ) operator:
@
Í
Press 8 ¸ to obtain a floating-
•
point result.
Activities
.
n
and
p=1000
) of an annuity where the starting
i
) is 6, and the future value (
n
) is
s
749