Suppose $\vec{v}_{1}, \vec{v}_{2}, \ldots, \vec{v}_{m}$ are arbitrary vectors in $\mathbb{R}^{n}$ Consider the transformation from $\mathbb{R}^{m}$ to $\mathbb{R}^{n}$ given by
\[
T\left[\begin{array}{c}
x_{1} \\
x_{2} \\
\vdots \\
x_{m}
\end{array}\right]=x_{1} \vec{v}_{1}+x_{2} \vec{v}_{2}+\cdots+x_{m} \vec{v}_{m}
\]
Is this transformation linear? If so, find its matrix $A$ in terms of the vectors $\vec{v}_{1}, \vec{v}_{2}, \ldots, \vec{v}_{m}$