Toyota Corp's stock is $$25$ per share. Its expected return is $22\%$ and variance is $10\%.$ Honda Corp's stock is $$18$ per share. Its expected return is $17\%$ and variance is $4\%.$ Benz Corp's stock is $$40$ per share. Its expected return is $10\%$ and variance $6\%.$ The covariance between Toyota and Honda is $0\mathrm{.}05.$ What would be the standard deviation of a portfolio consisting of $50\%$ Toyota and $50\%$ Honda?

Place your answer in decimal form, for example, as $0\mathrm{.}14256$ and not in percent form such as $14\mathrm{.}256\%.$