You are building two$-$asset portfolio out of the$$ risk$-$free asset and a risky asset, Stock X$.$ The$$ risk$-$free rate is $2\%,$ the expected return on Stock X is $9\mathrm{.}2\%,$ and its beta is $0\mathrm{.}9.$ You want the portfolio to have an expected return of $19\mathrm{.}6\%$ and a beta of $2\mathrm{.}2.$ You only have $$173$ to invest. How much do you have to borrow?