Recent content by grad

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    Undergrad Probability of L Consecutive Heads in N Coin Tosses

    Sorry mate but both your solutions are wrong. You can easily prove this if you try to find P(2,5) or P(1,5) or whatever you want... Does anybody know if such a formula even exists?
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    Undergrad Probability of L Consecutive Heads in N Coin Tosses

    Thank you for your answer but what exactly is [SIZE="4"]C?
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    Undergrad Probability of L Consecutive Heads in N Coin Tosses

    Well, I 've already seen that but I don't understand how these formulas work. Could you explain a little bit more if you can understand them?
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    Undergrad Probability of L Consecutive Heads in N Coin Tosses

    Thank you
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    Undergrad Probability of L Consecutive Heads in N Coin Tosses

    That's not correct. Let's suppose we toss a coin 3 times (N = 3) and we want a run of exactly 2 heads (L = 2). Then the combinations that include runs of HH are only two: THH and HHT The total combinations are 2N=3=8 So, P(2,3) = 2/8 = 1/4 Your answer gives 2-N= 1/8
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    Undergrad Probability of L Consecutive Heads in N Coin Tosses

    What is the probability that a run of exactly L consecutive heads (or tails) appears in N independent tosses of a coin? Please help me with this one... I 've searched everywhere but I can't find a general answer, for example P(L,N) = ...
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    Undergrad Understanding the Variance of a One-Dimensional Random Walk

    Thank you!
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    Undergrad Understanding the Variance of a One-Dimensional Random Walk

    Var(Sn) = E(Sn2) = E(Z12 + Z22 + Z32 + ... + Zn2) =* E(Z12) + E(Z22) + ... + E(Zn2) = 1 + 1 + ... + 1 (n times) = n *variables are independent and uncorrelated Is this correct then?
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    Undergrad Understanding the Variance of a One-Dimensional Random Walk

    Hi, I know that the expectation E(Sn) for a one-dimensional simple random walk is zero. But what about the variance? I read in http://en.wikipedia.org/wiki/Random_walk#One-dimensional_random_walk" that the variance should be E(Sn2) = n. Why is that? Can anyone prove it? Thank you...
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    Crack this code if you can* Challenging

    MATLAB code: ceil(400.*rand(1,36)) LOL!
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    High School Why is Radical i Squared Not Equal to -1?

    Thank you! I later found out that \sqrt[]{a*b}=\sqrt{a}*\sqrt{b} is NOT correct for NON-REAL numbers.
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    High School Why is Radical i Squared Not Equal to -1?

    I am sure that it's a stupid question that has already been answered in the past, but I couldn't find the solution anywhere. Well I want to know why the following attached equality is not true: