How to create a random geometric sample?

[Ignacio Benitez]

Hello, somebody knows how to create a random geometric sample?

[Bill Finzer]

Hello Ignacio,

Can you say more about what you mean by a “random geometric sample?” What do you want to sample from? And what should each sampled item be?

Bill

[Ignacio Benitez]

Something similar to what the  “randomgeometric()” function does in Fathom.

 

Thanks

[Bill Finzer]

Hello Ignacio,

Unfortunately, CODAP doesn’t have a random geometric function. I’m not sure why we didn’t include it and I’ll put it on our wishlist.

Your post made me curious to see if I could simulate the function. The unsatisfactory result is here. The numbers in the left table are generated from the simulated trials on the right and are resulting of computing the index of the first trial that succeeds where p is the probability of success.

The unsatisfactory part of the simulation is the difficulty of generating additional numbers! In the case table’s ruler menu you can choose to Rerandomize All. This generates new trials and new random geometric numbers, but there is no way to automatically record these numbers. You can add additional sets of trials, but it’s a painful process. Finally, of course, there is the possibility that even after 100 trials there is no success.

Constructing this simulation might be a good learning activity for students. If you try that, let us know the results!

Bill

[Ignacio Benitez]

Thaks a lot

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