Using the data in the following table, $,$ calculate the volatility $($standard deviation$)$ of a portfolio that is $61\%$ invested in stock A and $39\%$ in stock B$.$

The volatility of the portfolio is

$\%.($Round to two decimal places.$)$

Data table

$\backslash$table$[[($Click on the following icon $$ in order to copy its contents into a spreadsheet$)],[$Year$,2010,2011,2012,2013,2014,2015],[$Stock A$,-1\%,13\%,1\%,-5\%,2\%,9\%$