Calculation

What is $\langle x_{i}\rangle$ in the following expression?

X_{t}=\sum _{i=1}^{t}(x_{i}-\langle x_{i}\rangle )

The mean value of one variable $x_{i}$ , which would would be nothing else than $x_{i}$ , or of $x$ ? Please correct this. Herrkami (talk) 14:13, 1 March 2014 (UTC)[reply]

Calculation 2

The left-hand side of the equation

F(n)={\sqrt {{\frac {1}{N}}\sum _{t=1}^{N}\left(X_{t}-Y_{t}\right)^{2}}}.

contains $n$ while the right-hand side doesn't. Actually, this doesn't even look right as a piecewise computation...