Solution:
To find the standard deviation, the formula is
[tex]\begin{gathered} \sigma=\sqrt{npq} \\ n\text{ is number selected } \\ p\text{ is sucessful trials} \\ q\text{ is failed trials} \end{gathered}[/tex]Given
[tex]\begin{gathered} p=\frac{8}{100}=0.08 \\ q=1-0.08=0.92 \\ n=900 \end{gathered}[/tex]Substitute the values of the variables into the formula above
[tex]\begin{gathered} \sigma=\sqrt{npq} \\ \sigma=\sqrt{900\times0.08\times0.92} \\ \sigma=\sqrt{66.24} \\ \sigma=8.14\text{ \lparen two decimal places\rparen} \end{gathered}[/tex]Hence, the answer is 8.14 (two decimal places)