You own a stock portfolio invested $35$ percent in Stock Q$,30$ percent in Stock R$,20$ percent in Stock S$,$ and $15$ percent in Stock T$.$ The betas for these four stocks are $\mathrm{.}79,1\mathrm{.}17,1\mathrm{.}18,$ and $1\mathrm{.}35,$ respectively. What is the portfolio beta?