You hold a diversified $$100,000$ portfolio consisting of $20$ stocks with $$5,000$ invested in each. The portfolio's beta is $1\mathrm{.}12.$ You plan to sell a stock with b $=0\mathrm{.}90$ and use the proceeds to buy a new stock with b $=1\mathrm{.}25.$ What will the portfolio's new beta be$?$ Do not round your intermediate calculations.

Group of answer choices

$0\mathrm{.}853$

$1\mathrm{.}103$

$0\mathrm{.}956$

$1\mathrm{.}138$

$1\mathrm{.}285$