$($Q$3$B$)$ The table below provides the correlations between Green, a telephone$/$communication company located in Mexico, the Mexico stock market index, and the world market index, together with the standard deviations of returns and the expected returns. The risk$-$free rate is $5\%.$ Based on the stock market data in the following table, compute Green's world beta and cost of equity.

$\backslash$table$[[,$Green,Mexico,World,$\backslash$table$[[$Standard$],[$deviations of$],[$returns $(\%)]],\backslash$table$[[$Expected$],[$returns$],[(\%)$