P$2$

Over the past five years, Apple Inc $($APPL$)$ has earned annual returns of

$8\mathrm{.}3$ percent in year $1$

$9\mathrm{.}6$ percent in year $2$

$18\mathrm{.}25$ percent in year $3$

$-7\mathrm{.}7$ percent in year $4$

$1\mathrm{.}8$ percent in year $5$

What are the average return and standard deviation during this five$-$year sample period? $($To make calculation easier, you can directly work on numbers in percentage, such as $8\mathrm{.}3,$ not $0\mathrm{.}083.)$