You have a portfolio of a stock A and a stock B$.$ The beta of a stock A is $1\mathrm{.}2$ and the beta of a stock B is $0\mathrm{.}3.$ You invested $$300$ in stock A and $$700$ in stock $B.$ What is the portfolio beta?

$1\mathrm{.}26$

$1\mathrm{.}83$

$2\mathrm{.}24$

$3\mathrm{.}81$