Suppose that in $2024,$ there are three possible growth rates for the US economy: high, normal, low and the associated probabilities of the three scenarios are: $0\mathrm{.}6,0\mathrm{.}2,0\mathrm{.}2,$ respectively. Further assume that the return on the stock market during the year will be $20\%,5\%,$ and $-5\%$ respectively in these three scenarios, and the return on the $10-$year T$-$bond will be $2\%,6\%,$ and $8\%$ in these three scenarios. What are the standard deviations of stocks' and bonds' returns in $2024?$ What is the correlation coefficient between stocks' and bonds' returns?