Answer
$ 8s \sqrt {3}$
Work Step by Step
We first separate the number and the variable into two separate square roots:
$ \sqrt {192} \times \sqrt {s^{2}} = \sqrt {192} \times s$
In order to see if a radical is in simplified form, see if any of its factors are perfect squares (meaning that their square root will be an integer). We see that $\sqrt 192$ has factors of 64 and 3. 64 is a perfect square, so we know that we can simplify:
$s\sqrt {192} = s \times \sqrt {64} \times \sqrt {3} = 8s \sqrt {3}$