Q $11.$ Calculating Portfolio Betas. You own a stock portfolio invested $15$ percent in Stock Q$,25$ percent inQ$19.$Reward$-$to$-$Risk Ratios. Stock Y has a beta of $1\mathrm{.}25$ and an expected return of $12\mathrm{.}6$ percent. Stock $Z$ has a

beta of $\mathrm{.}85$ and an expected return of $10\mathrm{.}3$ percent. If the risk$-$free rate is $4\mathrm{.}1$ percent and the market risk

premium is $7$ percent, are these stocks correctly priced?

Stock R$,40$ percent in Stock S$,$ and $20$ percent in Stock T$.$ The betas for these four stocks are $\mathrm{.}85,\mathrm{.}91,$

$1\mathrm{.}31,$ and $1\mathrm{.}76,$ respectively. What is the portfolio beta?