Multiple measurement, or observation, as row or column vector

A multiple measurement or observation may be expressed as $$x=[\begin{matrix} 4 & 2 & 0.6 \\ \end{matrix}]$$ referring to the physical properties of length, width, and height, respectively.

The collection of measurements on  x  is called a vector. In this case it is a row vector. We could have written  x  as a column vector. $$x=\left[ \begin{matrix} 4 \\ 2 \\ 0.6 \\ \end{matrix} \right]$$