a$.$ "Given the above information, a rational investor should invest $20\%$ of

his$($her$)$ wealth in Tesla stock market if the expected return of monthly risk$-$

free rate of $0\mathrm{.}475$ percent and the Cov $($Tesla$,$ Samsung$)$ is $15.$ Is the

previous statement correct? Use $x_A$ and $x_B$ formulas discussed in the

lecture to explain your answer.

$x_A=\frac{\frac{|}{b}ar(R{)}_A-R_1|{}_B^2-\frac{|}{b}ar(R{)}_B-R_1|{}_{AB}}{\frac{|}{b}ar(R{)}_A-R_1|{}_B^2+\frac{|}{b}ar(R{)}_B-R_1|{}_A^2-\frac{|}{b}ar(R{)}_A-R_J\frac{+}{b}ar(R{)}_B-R_1|{}_{AB}}$