Scaling matrix is:

$M=\left[\matrix{0.5\quad 0\cr 0\quad 1.5}\right]$

Here,

Horizontal scaling factor is:

$S_x=0.5=\frac{1}{2}$

So, horizontal value becomes half.

Therefore, statement $4$ is true.

Vertical scaling factor is:

$S_y=1.5=\frac{3}{2}$

So, vertical value increases by three halves.

Therefore, statement $2$ is true.

Correct statements are:

$2$ and $4$