I have 2 groups of people. I'm working with the data about their age. I know the means, the standard deviations and the number of people. I don'...

Context : This post is the first of a series of posts taking their origins from the exercises in the Revuz and Yor's Book "Continuous Martingales ans...

I am looking for an accurate algorithm to calculate the error function $$\operatorname{erf}(x)=\frac{2}{\sqrt{\pi}}\int_0^x e^{-t^2}\ dt$$ I have tried us...

If I have to observe a queue at an electronics shop and I need to perform at least 10 observations, how can I determine what the mean rate of arrival is? ...

In class we learnt that for a binomial experiment, the standard deviation is equal to $\sqrt{npq}$. Is there a way to derive/prove this? I have a basic un...

I have found from a site this formula: Ok.I have found that this formula is correct.see the reason below. This part of formula is always $1$ or $zero$. it...

Let's start with the Cambridge Dictionary definitions of the words, indefinite and indefinitely: indefinite: not exact, not clear, or without clear l...

Let $A$ be an $m\times n$ matrix, what condition on the dimensions $m$ and $n$ is necessary for the quantity $(A^t\times A)^{-1}$ to exist? Please kindly ...

I can solve for a, b, c given three points for a parabola for example (1,1)(2,4)(3,9) but i need to create a program which returns a,b,c in the form: $$y ...

I am having a hard time understanding when to use each different subgroup test and if given at any case, its sufficient to use either to proof that the gi...