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Forum: General Questions - Industry/Practice
Welcome to the General Questions - Industry/Practice forum!
Questions arising from real-world applications.

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Elevator Stochastic Problem by Fpino on 2009-05-29 16:44:25
Hi I need help with this problem:

The number of people entering an elevator on the first floor of the building is a Poisson random variable with mean lambda.
If the building has N floors, excluding the first floor, and the probability that one person get down on the floor x was the same for each floor, determine the expected value of stops where the elevator is empty. The lift takes people only on the first floor.
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help by a1160831 on 2009-05-14 02:51:07
hey all,
i'm looking for a probability distribution that is like a binomial distribution but has more than just replacement. that is if i refer to the urn model if i take out a black ball i put back 1+f(x) black balls, where f(x) is a function of some known variable x.
any help would be appreciated.
thanks
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Power series - what does the notation mean? by ed33 on 2009-03-27 00:48:48

I have to compute sums of four series (programmatically). All I have is this:

J1 = (3e1/2 - 27e13/32 ..)
J2 = (21e12/16 - 55e14/32 ..)
J3 = (151e13/96 ..)
J4 = (1097e14/512 ..)

So far in such cases I was finding a relation between the following elements of the sum and created a loop that did the job (Is there a better way??). Now, as I have very few elements of the above I need to find the 'general rule' that would work for all four. Could you help?
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Rotating Multiple Boxes by fractorr on 2009-01-26 23:12:58
I am trying to figure out how to calculate the top left X,Y coordinates of multiple boxes using the center X,Y position of all the selected boxes as the origin of the rotation.
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Probability calc by jfs on 2009-01-14 09:42:31
Hi, hope someone can help! In an automotive application, an emissions monitor tests a system intermittently. If the system is faulty then the 'check engine' light must be illuminated on the dashboard.

The legislation says that if the fault is detected on 2 successive occasions then the light must be lit. This is so that one rogue result doesn't light the light.

Let us say there is a fault with the system being monitored. When there is a fault, the monitor correctly diagnoses it 70% of the time. If the monitor runs, say, 10 times, what is the probability that there will have been 2 successive detections of the fault.

I can compute the probability of 2 or more detections in 10 trials using the Binomial distribution. Integrating nCx . p^x . q^(n-x) for x = 2:n, where n=10, p = 0.7; q = 1-p.

But this obviously isn't the answer because the 2 detections need to be CONSECUTIVE. So, how do I calc the probability?

It seems like it should be really simple but I'm not a mathematician and therefore not clever enough to see it!

Justin
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