whats it the square root of 328.29 rounded to 3 significant figures
$${\sqrt{{\mathtt{328.29}}}} = {\mathtt{18.118\: \!774\: \!793\: \!015\: \!117\: \!1}}$$
To 3 significant figures this is 18.1
(Don't confuse this with 3 decimal places which would be 18.119)