+ Reply to Thread
Results 1 to 3 of 3

Thread: Probability growth with time

  1. #1
    Points: 4, Level: 1
    Level completed: 7%, Points required for next Level: 46

    Posts
    1
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Probability growth with time




    Hey, I am not an expert at probability. I've been wondering about a simple question that seem really hard for me to find an answer to simply by googling. There really is no easy way to put my question, so I’m going to just state an example. Say we want to find the probability of a car accident happening in a certain amount of time, how would we go about solving that? I know this would depend on the driver’s skill, places that he drives, etc. But even if we figured all that out, we would still have a problem. Normally a probability is calculated as a possible outcome over a number of possible outcomes. So say the chance of getting a head is because there it is 1 out of 2 possible outcomes, WHEN you toss a coin. But the above question is different, we did not define the WHEN. The when is more like.. a continuous event. I would expect the theory that corresponds to this to be something like a growth curve of possibility that approaches 100% when t->infinity.

    EDIT: Please keep it simple, because I don't know a lot about statistics.
    Last edited by elite5chris; 04-16-2014 at 04:05 PM.

  2. #2
    TS Contributor
    Points: 22,410, Level: 93
    Level completed: 6%, Points required for next Level: 940

    Posts
    3,020
    Thanks
    12
    Thanked 565 Times in 537 Posts

    Re: Probability growth with time

    One very common modelling, e.g. is to model the time needed for the accident to happen following a certain exponential distribution.

    Then in this case the probability that the accident happen in the time interval is the probability that the exponentially distributed accident happening time is less than the length of the interval.

    Whenever you have learn some basic of continuous random variable, you should get some rough idea. The "growth curve" you mentioned I guess would be the CDF of a continuous distribution which is a continuous function. And for a continuous distribution, unlike discrete distribution, it has uncountably many support points but has no point mass inside - the probability that the continuous random variable equal to a particular support point is zero.

  3. #3
    TS Contributor
    Points: 14,811, Level: 78
    Level completed: 91%, Points required for next Level: 39
    Miner's Avatar
    Location
    Greater Milwaukee area
    Posts
    1,171
    Thanks
    34
    Thanked 405 Times in 363 Posts

    Re: Probability growth with time


    This is a form of Survival Analysis. In reliability, the growth curve is called a Cumulative Failure Plot. This handbook may help.

+ Reply to Thread

           




Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats