Suppose you have a portfolio that has $$290$ in stock A with a beta of $1\mathrm{.}04,$ $$1,160$ in stock B with a beta of $1\mathrm{.}34,$ and $$870$ in the risk$-$free asset. You have another $$580$ to invest. You wish to achieve a beta for your whole portfolio to be the same as the market beta.

What is the beta of the added security?