E-CodeGeometric distribution: first success — a TI-84 Plus CE program
GEOMPROB is a TI-BASIC program for the TI-84 Plus CE. Chance the first success comes on trial k, by trial k, or after trial k, with the mean and standard deviation of the waiting time.
What it asks for and what it shows
It asks for 2 values at its prompts. In the example below it shows P(X=K), P(X≤K), P(X>K), MEAN, SD.
Example run
One of its oracle test cases: “p .2, first success on trial 3”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | 0.2 |
| Input 2 | 3 |
| The screen shows | |
P(X=K)= | 0.128 |
P(X≤K)= | 0.488 |
P(X>K)= | 0.512 |
MEAN= | 5 |
SD= | 4.472135955 |
How it's checked
5 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 31 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 “Geometric distribution: first success” (GEOMPROB).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Binomial, Poisson and normal probabilities
- 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