Two stocks X and Y with the same standard deviation of returns $\backslash$sigma $=0\mathrm{.}88$ and correlation coefficient of their returns pXY $=-0\mathrm{.}45.$ Calculate the result of diversifying two portfolios consisting of stocks X and Y in ratios of $0\mathrm{.}30-0\mathrm{.}70$ and $0\mathrm{.}50-0\mathrm{.}50$ respectively. How do you comment on the comparison of results?