Understanding sum of square deviations
98064
Why is the sampling distribution of variance a chi-squared distribution?
147795
$\sum x_n^2$ and $\sum y_n^2$ converge, what does $\sum (x_n + y_n)^2$ do?
75995
Infinite Sum - Result not correct for all cases?
137109
Evaluating a summation of inverse squares over odd indices
121661
Evaluating the sum $\Sigma \, \frac{1}{k(k+p)}$
93922
sum of noncentral Chi-square random variables
109310
Understanding “the mean minimizes the mean squared error”
63391
How to compute the sum of random variables of geometric distribution
64720
Expected value of sums
144568
How closely can we estimate $\sum_{i=0}^n \sqrt{i}$
112001
The sum of $n$ independent normal random variables.
146333
Gaussian proof for the sum of squares?
77517
Why is this sum a representation of e?
18975
How to 'sum' a standard deviation?
140433
The number of ways of writing an integer as a sum of two squares
1301
Expected value and standard deviation of $X^2$ in terms of moments of $X$
114173
Explanation of the formulas for sums $\sum nr^n$ and $\sum n^2 r^n$