Currently i did some work with a data set within Java script. I need help writing an equation for some math. Lets say there is List of devices, lets call them X, X1, X2, X3, and so on. Each X has a community(500+) of values assigned to it. lets call those y. To get my ending result I added up all values(y) assigned to X and then divided that by the total number of Y values assigned to ALL x values.
How would this be written in equation form? I appreciate any help!
Let the values for $X$ be $X_i$, so they are indexed by $i$, and there be $n$ of them. Then the sum of all the values would be $S(X)=\sum_{i=1}^nX_i$. You could give $S(X)$ a different name if you want. Your final value is then $$\frac {S(X)}{S(X)+S(X1)+S(X2)+S(X3)}$$