Toyota Corp's stock is $$32$ per share. Its expected return is $22\%$ and variance is $13\%.$ Honda Corp's stock is $$21$ per share. Its expected return is $17\%$ and variance is $4\%.$ Benz Corp's stock is $$40$ per share. Its expected return is $15\%$ and variance $7\%.$ The covariance between Toyota and Honda is $0\mathrm{.}03.$ What would be the standard deviation of a portfolio consisting of $50\%$ Toyota and $50\%$ Honda?