Consider an economy in which there is only a single factor influencing returns on all well diversified portfolios.

Portfolios A and $B$ have expected returns of $13\%$ and $16\%,$ respectively.

The risk$-$free rate of return is $4\%.$

Portfolio B has a beta of $1\mathrm{.}0$ on the single factor.

If arbitrage opportunities are ruled out, what is the beta of portfolio A on the single factor?

Answer: