E-CodeChi-square goodness of fit — a TI-89 Titanium program
CHISQ89 is a TI-89 BASIC program for the TI-89 Titanium. Observed counts and expected counts (or proportions) as lists: chi-square, degrees of freedom, the p-value from your own Define'd function (exact series for whole-number df), and a warning when an expected count is under 5.
What it asks for and what it shows
It asks for 2 values at its prompts. In the example below it shows CHI², DF, P, MIN E.
Example run
One of its oracle test cases: “fair die, 120 rolls (5 df)”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | {18,24,16,25,17,20} |
| Input 2 | {20,20,20,20,20,20} |
| The screen shows | |
CHI²= | 3.5 |
DF= | 5 |
P= | 0.6233876277 |
MIN E= | 20 |
How it's checked
4 test cases, each checked against an independent method. Replayed key by key on a virtual TI-89 Titanium, they make 22 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-89 Titanium calculator and pick “Chi-square goodness of fit” (CHISQ89).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- t test and interval from data lists
- One-sample z test and interval (dialog)
- Linear regression with exact slope
- Least-squares polynomial fit (exact)
- One-variable statistics of a list
All TI-89 Titanium statistics programs · All TI-89 Titanium programs