Given the mean and standard deviation below
[tex]\begin{gathered} \sigma\text{ is standard deviation} \\ \mu\text{ is the mean } \end{gathered}[/tex]The formula for standard deviation is
[tex]\sigma=\sqrt[]{Variance}[/tex]Given that
[tex]\text{Variance}=10.5[/tex]Substitute for Variance into the formula for standard deviation
[tex]\begin{gathered} \sigma=\sqrt[]{10.5} \\ \sigma=3.24\text{ (two decimal places)} \end{gathered}[/tex]Hence, the standard deviation, σ is 3.24 (two decimal places)