Summation

[SerKin0]

Hello, I am currently working on a program that will calculate errors in my laboratory work. And several formulas use a certain summation of elements with additional calculations, for example: Σ(t_i - t_ average)^2, where t_ is the average number, and t_i is an element of the data array. Please tell me how to make such a summation so that it turns out (t_1 - t_ average)^2 + (t_2 - t_ average)^2 + (t_3 - t_ average)^2 + ...

Thanks in advance!