E-CodeBinomial, Poisson and normal probabilities — a TI-84 Plus CE program
PROBDIST is a TI-BASIC program for the TI-84 Plus CE. Binomial and Poisson P(X=a), P(X≤b), P(a≤X≤b), P(X≥a) with mean and SD; normal P(a<X<b), tails and z-scores; inverse normal for a left area, plus the central interval.
What it asks for and what it shows
It asks for 4 values at its prompts, after you pick option 1 from its menu. In the example below it shows MEAN, SD, P(X=A), P(X≤B), P[A,B], P(X≥A).
Example run
One of its oracle test cases: “binomial 10 flips p .5, 3..6 heads”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Menu | option 1 |
| Input 1 | 10 |
| Input 2 | 0.5 |
| Input 3 | 3 |
| Input 4 | 6 |
| The screen shows | |
MEAN= | 5 |
SD= | 1.58113883 |
P(X=A)= | 0.1171875 |
P(X≤B)= | 0.828125 |
P[A,B]= | 0.7734375 |
P(X≥A)= | 0.9453125 |
How it's checked
12 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 75 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-84 Plus CE calculator and pick “Binomial, Poisson and normal probabilities” (PROBDIST).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Geometric distribution: first success
- Normal approximation to the binomial
- Regression: linear, quadratic, exponential with r²
- Hypothesis tests: z, t, two-sample t, chi-square
- Confidence intervals: z, t, proportion, two-sample
All TI-84 Plus CE statistics programs · All TI-84 Plus CE programs