Incorrect. Each of the radicands falls between the perfect squares 16 and 25, so each square root is between $\displaystyle\sqrt{{{16}}}\usepackage{cmbright}\Huge\$ and $\displaystyle\sqrt{{{25}}}\usepackage{cmbright}\Huge\$ , or between 4 and 5. Determine whether each radical expression is closer to 4 or 5 to make an initial estimate. Then try squaring the approximations to find the best estimate for each radical expression.