Recent content by tim8691

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    Need statistics help working with normal distribution

    Thanks so much bpet, I believe your solution above solves the equation: (p(Q))N = C as I've defined on page 2 of the attached document. This Q is the probability of running one experiment of population N and computing the range (e.g. 2Q) of the normally distributed random variable x...
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    Need statistics help working with normal distribution

    Hmm, not sure why it didn't take. I'll try again.
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    Need statistics help working with normal distribution

    Hello experts, Thanks to discussions with Stephen Tashi for getting me this far. See the problem statement in the attached PDF page 1. I need help solving for Qc in equation form, as a function of the other variables (N and C), preferably using erfc so I can program an accurate algorithm...
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    Calculating Width of Gaussian PDF(x) Given Sigma & N

    Wow, that's great Stephen. At first I was skeptical because of working with 1-(very small number), but in the end with the Taylor expansion of ex = 1+x, the 1 - ex simplifies to -x. Brilliant!
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    Calculating Width of Gaussian PDF(x) Given Sigma & N

    Thanks again Stephen, If we use the Normal distribution with mean = 0 and sigma = 1, then the distribution N(x) simplifies to N(x) = (1/(sqrt(2*pi))*e(-x*x/2) If we can insert this into the appropriate "complementary" equation, then re-arrange terms and/or do a change of variables to...
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    Calculating Width of Gaussian PDF(x) Given Sigma & N

    Thanks Stephen, (p(m))N=0.95 This equation is along the right track, thanks!. But, I find this places me working with numbers very close to 1. This is a problem because my values of N are very large, and there's only 16 digits in a computer's representation of a double-precision number...
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    Calculating Width of Gaussian PDF(x) Given Sigma & N

    Hi Stephen, I think you're right. Let's set mu to 0 here (e.g. the mean of the distribution is 0). For a random variable X with a given normal distribution N(mu=0,sigma), find an interval (-R,R) such that there is a 95% chance that when a given number n independent samples of X are taken...
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    Calculating Width of Gaussian PDF(x) Given Sigma & N

    Hi Stephen, Thanks for your comments. Using your terminology, I want to compute the Nth order statistic multiplied by 2. That is, if we conduct N experiments of random variable x having normal distribution (mean=0), what's the largest value of x we'll observe (assuming some confidence level, or...
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    Calculating Width of Gaussian PDF(x) Given Sigma & N

    Hi Experts, I'm working in industry and have an application requiring some expert knowledge on statistics/probability. I have a probability distribution function (PDF) for a Gaussian random variable. I know the standard deviation of the PDF. I also know total number of experiments conducted...
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