You own a stock portfolio invested $20$ percent in Stock Q$,20$ percent in Stock R$,40$ percent in Stock S$,$ and $20$ percent in Stock T$.$ The betas for these four stocks are $\mathrm{.}90,\mathrm{.}96,1\mathrm{.}36,$ and $1\mathrm{.}81,$ respectively. What is the portfolio beta?