SR-56 Annuity Program - Interest Rate Unknown
This program is taken from the SR-56 Applications Book, by Texas Instruments.

This will solve for the periodic interest rate given the N, PV, and PMT components of the Time Value of Money. Remember: The periodic interest rate is NOT the annual rate. If you are solving for the interest rate and the payments are monthly, you will get a monthly interest rate as the answer. To convert to an annual rate, you will have to multiply by 12! To solve the TVM problem involving a Future Value, see: SR-56 Future Values

Instructions:
1) Clear memories. 2nd Cms.
2) Load known values (you need to enter three of these) into data memories. Present Value STO 2, Payment per period, STO 3, Number of periods STO 4.
3) Calculate the periodic interest rate by pressing RST, R/S. The interest rate per period is automatically calculated and displayed.

Program Listing:
```Line  Keycode  Instruction
00      56       CP
01      15       CLR
02      34       RCL
03      03       3
04      54       /
05      34       RCL
06      02       2
07      74       -
08      20       1/X
09      33       STO
10      05       5
11      54       /
12      34       RCL
13      04       4
14      43       X^2
15      94       =
16      37       X = T
17      09       9
18      04       4
19      33       STO
20      01       1
21      34       RCL
22      01       1
23      64       *
24      34       RCL
25      05       5
26      74       -
27      52       (
28      01       1
29      74       -
30      52       (
31      01       1
32      84       +
33      34       RCL
34      01       1
35      53       )
36      45       Y^X
37      34       RCL
38      04       4
39      93       +/-
40      53       )
41      33       STO
42      06       6
43      94       =
44      54       /
45      52       (
46      34       RCL
47      06       6
48      54       /
49      34       RCL
50      01       1
51      74       -
52      52       (
53      34       RCL
54      04       4
55      64       *
56      52       (
57      01       1
58      84       +
59      34       RCL
60      01       1
61      53       )
62      45       Y^X
63      52       (
64      34       RCL
65      04       4
66      93       +/-
67      74       -
68      01       1
69      94       =
70      12       INV
71      35       SUM
72      01       1
73      28       | X |
74      74       -
75      04       7
76      93       +/-
77      19       10^X
78      94       =
79      47       X >= T
80      02       2
81      01       1
82      34       RCL
83      01       1
84      49       FIX
85      06       6
86      44       EE
87      12       INV
88      44       EE
89      33       STO
90      01       1
91      64       *
92      02       2
93      19       10^X
94      49       FIX
95      02       2
96      41       R/S
97      42       RST
```

Visitors since 6/21/97