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# probability question

Discussion in 'The Okie Corral' started by gwalchmai, Apr 18, 2012.

1. ### gwalchmaiLucky Member

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If you drop a screw (2mm long by 1mm wide with a 2mm head) in a room 12ft x 16ft with 75% of the floor covered with cabinets, what is the probability of stepping on that screw? Assume a size 11, EEE shoe.

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100%.

3. ### IndianaMatt

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DevilDog should be here soon to handle this.

4. ### DanaTPharaoh

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You are "almost" correct because he did not give an amount of tries in which to have a sucess.

This means the limit of tries will approach infinity and therefore the probability will approach the limit (which is nearly 100% but never quite there 99.99999999999999999999999999999999999999999999999%+ but never hits 100%)

-Dana

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You forgot to add a timeframe.

Also, can said screw roll under anything? If that the answer is yes, then your chances are better you won't screw your foot.

6. ### cj5mrt

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In my case, if it was a screw I needed to finish a project and I had no others to replace it, there is zero chance of stepping on it, much less finding it.

7. ### gwalchmaiLucky Member

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OK. I assumed everyone understood that I want the probability of stepping on the screw with any random step. I guess I was being optimistic...

ETA: no, the screw will not roll under anything.

Last edited: Apr 18, 2012

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Probably.

9. ### janice6Silver Member

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When I drop a screw it always lands where I'm not looking.

Then later, after fruitless efforts, I look where I should have to begin with and there it is.

10. ### Geko45Smartass PilotCLM

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As much screw as wood screw could screw if a wood screw could screw wood.

11. ### RayBRetired Member

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Have you slept at all in the last, say, 72-hours?

--Ray

12. ### DanaTPharaoh

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You still have not addressed if you are asking for the probability of an outcome with a single trial or if you are asking about the cumlative probability with an undefined or defined amount of trials.

You question is much to vague to answer.

Also, what is the underlying assumptions? Can the screw be randomally placed anywhere in the room or is it more likely to be near where it was dropped? Are you assuming the equal likelyhood of walking right next to a wall on the far side of the room as walking through the door into the room?

Basically, this is a VERY complex scenario that you have to spacially oriented probabilities and the most likely way of solving the intersection of the two is monte-carlo simulations.

-Dana

13. ### SC TigerJive Tiger

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It's always in the last place you looked.

Because if you keep looking for something after you found it you've got problems.

14. ### SC TigerJive Tiger

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Point up, with it going through your foot.

Murphy is an ***.

15. ### jvbronco

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For those iPhone 4 owners: try saying this to Siri (the wood chuck version)- its hilarious to hear the phone repeat it.

Outdoor Hub mobile, the outdoor information engine

16. ### gwalchmaiLucky Member

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Single trial.
Assume random placement
Assume random foot placement anywhere in the room.

You may use any modeling technique you choose.

17. ### John's 26

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If you're wearing shoes, less probability. Barefoot? almost certian...

18. ### PuroMexicanoVIVA MEXICO !!!

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Your question should be the probability to finding it when looking for it vs the probabiliy of stepping on it barefoot.

0 to 100

19. ### tousGET A ROPE!

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See the Markov Monte Carlo pattern for a definitive maybe.

The previous posters are correct in noting that there is not enough information to make a reasonable conclusion.

What is the length of your average stride?

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