says that ``the second moment around \(t\) is equal to the second moment around the mean \(\expec X\) plus the square of the distance between \(t\) and the mean''. Note that this is analogous to (and ...says that ``the second moment around \(t\) is equal to the second moment around the mean \(\expec X\) plus the square of the distance between \(t\) and the mean''. Note that this is analogous to (and mathematically equivalent to) the Huygens-Steiner theorem (also called the Parallel Axis theorem) from mechanics, which says that ``the moment of inertia of a body with unit mass around a given axis \(L\) is equal to the moment of inertia around the line parallel to \(L\) passing through the center…
