Problem $11-10$ Calculating Portfolio Betas

You own a stock portfolio invested $30$ percent in Stock Q$,30$ percent in Stock R$,30$ percent in Stock S$,$ and $10$ percent in Stock T$.$ The betas for these four stocks are $\mathrm{.}82,1\mathrm{.}20,1\mathrm{.}21,$ and $1\mathrm{.}38,$ respectively. What is the portfolio beta? $($Do not round intermediate calculations and round your answer to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

Portfolio beta