ou own a stock portfolio invested $20$ percent in Stock Q$,25$ percent in Stock R$,15$ percent in Stock S$,$ and $40$ percent in Stock T$.$ The betas for these four stocks are $1\mathrm{.}11,1\mathrm{.}34,0\mathrm{.}83,$ and $1\mathrm{.}53,$ respectively. What is the portfolio beta?