Elinore is asked to invest $ $5$ comma $000$ in a$$ friend's business with the promise that the friend will repay $ $5$ comma $500$ in one year. Elinore finds her best alternative to this$$ investment, with similar$$ risk, is one that will pay her $ $5$ comma $400$ in one year. U$.$S$.$ securities of similar term offer a rate of return of $7\%.$ What is the opportunity cost of capital in this$$ case?