$1.(15$ points$)$ Suppose stock ABC has an expected return of $20\%$ and a standard deviation of $40\%.$ Stock XYZ has an expected return of $30\%$ and a standard deviation of $60\%.$ The two stocks have a correlation of $0\mathrm{.}3.$ What is the standard deviation of a portfolio that is split $60\%$ invested in ABC and $40\%$ invested in XYZ$?$