Using the data from Table $12\mathrm{.}3,$ what is the volatility of an equally weighted portfolio of Coca $-$ Colaand Starbucksstock?

The volatility of the portfolio is $\%.($Round to one decimal place.$)$

Data table

TABLE $12\mathrm{.}3$

Estimated Annual Volatilities and Correlations for Selected Stocks

$($Based on Monthly Returns, January $2009-$December $2018)$

Source: Authors' calculations based on data from Yahoo Finance.