A stock has produced returns of $11$ percent, $4$ percent, $-5$ percent, $-8$ percent, and $9$ percent for the past five years, respectively. What is the standard deviation of

these returns?

Multiple Choice

$8\mathrm{.}49\%$

$7\mathrm{.}52\%$

$4\mathrm{.}20\%$

$8\mathrm{.}41\%$