Texas Instruments TI-89 Titanium User Manual

Activities 749
Finding the Interest Rate of an Annuity
Perform the following steps to find the interest rate (
i) of an annuity where the starting
principal (
p) is 1,000, number of compounding periods (n) is 6, and the future value (s) is
2,000.
1. On the Home screen, enter the equation
to solve for
p.
2. Enter the equation to solve for
n.
3. Enter the equation to solve for i using the
with operator.
solve(s=p†(1+i)^n,i) | s=2000 and p=1000
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.

Texas Instruments TI-89 Titanium Specifications

General

Display Type	LCD
Display Resolution	160 x 100 pixels
CPU	Motorola 68000
CPU Speed	16 MHz
RAM	256 KB
Flash ROM	2.7 MB
Programming Language	TI-BASIC, Assembly
Power Source	4 AAA batteries
Connectivity	I/O port
Dimensions	7.5 x 3.5 x 1 inches