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Thread: If there are 50 people and the odds of turning up are 0.34 what is the variance?

  1. #1
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    If there are 50 people and the odds of turning up are 0.34 what is the variance?

    Hey,

    If there are 50 people and the odds of turning up are 0.34 what is the variance?


    Thanks,

  2. #2
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    Quote Originally Posted by egray View Post
    Hey,

    If there are 50 people and the odds of turning up are 0.34 what is the variance?


    Thanks,
    What are your thoughts?

    Please share your work with us ...even if you know it is wrong.

    If you are stuck at the beginning tell us and we'll start with the definitions.

    You need to read the rules of this forum. Please read the post titled "Read before Posting" at the following URL:

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    “... mathematics is only the art of saying the same thing in different words” - B. Russell

  3. #3
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    Quote Originally Posted by egray View Post
    Hey,

    If there are 50 people and the odds of turning up are 0.34 what is the variance?


    Thanks,
    I haven't dealt with odds for a while but isn't odds the ratio or comparison of two numbers? How can the odds be 0.34?

    Odds are like 3 to 1 or 5 to 2 Not 7

    I think it should be that the probability of turning up is 0.34

    So what is the 0.34 telling you? What is the formula for the variance and how does the 0.34 help you find the variance?
    Last edited by Jomo; 03-05-2018 at 09:48 PM.
    A mathematician is a blind man in a dark room looking for a black cat which isn’t there. - Charles R. Darwin

  4. #4
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    Quote Originally Posted by egray View Post
    Hey,

    If there are 50 people and the odds of turning up are 0.34 what is the variance?


    Thanks,
    This question is too vague. First it says there are 50 people, which makes it sound like you know exactly how many people are present in this (unknown) situation. So there is nothing probabilistic about the situation, so how can there be variance? Then it says the odds (which I'll interpret to mean the probability) of showing up is 0.34. Probability of who, showing up where? Does this have anything to do with the place that has 50 people in it? What is the variance in what?

    We need the exact problem statement in order to help you, and I doubt very much that this was it.

    I can try to guess at what you meant, not that there is much point to it. But, for example, if you meant that 50 people were invited to an event, but each one only has a 0.34 chance of actually showing up, then the number of people who do show up is described by a certain type of random variable. Which type would it be? (You tell me). I know what the expected value is for the number of people who will show up, but there is, in that case, also a variance to that random variable, that is calculable.

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