Respuesta :

We just have to use the following formula

[tex]\sigma=\sqrt[]{n\cdot P\cdot(1-P)}[/tex]

Where n = 70 and P = 0.7.

[tex]\begin{gathered} \sigma=\sqrt[2]{70\cdot0.7\cdot(1-0.7)}=\sqrt[]{49(0.3)}=\sqrt[]{14.7} \\ \sigma=3.8 \end{gathered}[/tex]

Hence, the standard deviation is 3.8.