5.3 Center of Gravity
For every cloud of points, there is an average point, called the center of gravity.
If the points have an associated weight (\(p_i\) for individual \(i\)), the coordinate of the center of gravity on the \(i\) axis is:
\[ G_j = \sum_{i=1}^{n} p_i \hspace{1mm} x_{ij} \]
The center of gravity corresponds the statistical notion of mean or average point.