Toyota Corp's stock is $$28$ per share. Its expected return is $20\%$ and variance is $13\%.$ Honda Corp's stock is $$22$ per share. Its expected return is $15\%$ and variance is $6\%.$ Benz Corp's stock is $$48$ per share. Its expected return is $12\%$ and variance $8\%.$ The covariance between Toyota and Honda is $0\mathrm{.}06.$ 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 $14\mathrm{.}256\%.$